Describing Motion Around Us Class 9 Worksheet with Answers Science Chapter 4

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Class 9 Describing Motion Around Us Worksheet

Worksheet On Describing Motion Around Us Class 9

Describing Motion Around Us Worksheet Class 9

→ Motion in a Straight Line: When an object moves in a straight line, its motion is called linear motion or motion in a straight line.

→ Describing Position: The method of specifying the location of an object using a reference point.

→ Reference Point: A fixed point or location used to compare and describe the position of other objects.

→ Rest: Position with respect to the reference point does not change.

→ Motion: Position with respect to the reference point changes.

→ Instant of Time: A single reading of a clock at a given point of time.

→ Distance Travelled: The total length of the path covered by an object during motion. It is a scalar quantity and is measured in metres (m).

→ Displacement: The shortest straight-line distance between the initial and final positions of an object, along with direction.

→ Magnitude: Numerical value (with units) of such a physical quantity.

→ Scalar Quantity: A physical quantity that has only magnitude (size) and no direction.

→ Vector Quantity: A physical quantity that has both magnitude and direction.

→ Uniform Motion: Motion in which an object covers equal distances in equal intervals of time, no matter how small the time interval is.

→ Non-uniform Motion: Motion in which an object covers unequal distances in equal intervals of time.

→ Speed: The rate at which an object covers distance. It is calculated as distance divided by time and is a scalar quantity. Speed = Distance / Time

→ Average Speed: The total distance travelled divided by the total time taken during the motion of an object.

→ Velocity: The rate of change of displacement with time. It includes both magnitude and direction, making it a vector quantity.

→ Average Velocity: The total displacement divided by total time taken. It depends on the net change in position, not the total path length.

→ Acceleration: The rate of change of velocity with time. It can occur due to a change in speed, direction, or both. Acceleration = (Final velocity – Initial velocity) / Time

→ Average Acceleration: Total change in velocity divided by the total time taken.

→ Uniform Acceleration: When the velocity of an object changes by equal amounts in equal intervals of time.

→ Non-uniform Acceleration: When the velocity changes by unequal amounts in equal intervals of time.

→ Retardation (Deceleration): Negative acceleration, it occurs when an object slows down.

→ Graphical Representation of Motion: The use of graphs to visually show how quantities like position, velocity, and acceleration change with time.

→ Position-Time Graph (Distance-Time Graph): A graph that shows how the position (or distance) of an object changes with time.
· A straight line indicates uniform motion.
· A curved line indicates non-uniform motion.

→ Velocity-Time Graph: A graph that shows how velocity changes with time.
· A straight horizontal line indicates constant velocity.
· A sloping line or non- straight line indicates acceleration.

→ Slope (Gradient): The steepness of the line in a graph.
· In a position-time graph, slope represents velocity.
· In a velocity-time graph, slope represents acceleration.

→ Area under the Graph: The space between the graph line and the time axis.
· In a velocity-time graph, it represents displacement.
· In a speed-time graph, it represents distance.

→ Kinematic Equations: A set of equations used to describe motion in a straight line with constant acceleration:
· v = u + at
· s = ut + \(\frac{1}{2}\)at²
· v² = u² + 2as

where:
u = initial velocity,
v = final velocity,
a = acceleration,
t = time,
s = displacement

→ Motion in a Plane: Motion that occurs in two dimensions (along both x-axis and y-axis).

→ Uniform Circular Motion: Motion of an object along a circular path at constant speed. Even though speed is constant, velocity changes due to a continuous change in its direction.

Class 9 Science Exploration Chapter 4 Worksheet

Class 9 Science Describing Motion Around Us Worksheet

A. Multiple-Choice Questions

Question 1.
A car travels 5 km north, then 12 km east, and finally 5 km south. What is the magnitude of its displacement from the starting point?
(a) 22 km
(b) 12 km
(c) 10 km
(d) 5 km

Question 2.
A runner completes one full lap of a circular track of radius 50 m. Select the correct option,
(a) Distance = 100 m, Displacement = 0
(b) Distance = 314 m, Displacement = 0
(c) Distance = 314 m, Displacement = 100 m
(d) Distance = 100 m, Displacement = 100 m

Question 3.
A car travels 60 km in 2 hours, then 40 km in one hour, all along a straight roa(d) What is its average speed?
(a) 30 km/h
(b) 33.3 km/h
(c) 40 km/h
(d) 50 km/h

Question 4.
A car travels 200 km north in 3 hours, then 200 km south in 2 hours. What are its average speed and average velocity for the entire trip?
(a) Average speed = 80 km/h, Average velocity = 0 km/h
(b) Average speed = 80 km/h, Average velocity = 20 km/h north
(c) Average speed = 40 km/h, Average velocity = 0 km/h
(d) Average speed = 40 km/h, Average velocity = 20 km/h south

Question 5.
Which condition ensures that the magnitude of average velocity is equal to the average speed?
(a) Motion along a straight line without reversal.
(b) Motion along a circular path.
(c) Motion in which the direction changes during motion.
(d) Motion along a curved path is zero.

Question 6.
A bus increases its velocity from 10 m/s to 25 m/s in 5 seconds. What is its average acceleration?
(a) 3 m/s²
(b) 5 m/s²
(c) 7.5 m/s²
(d) 15 m/s²

Question 7.
Which statement is correct about acceleration?
(a) An object moving fast must have high acceleration.
(b) An object moving at constant velocity has zero acceleration.
(c) Acceleration depends only on speed, not direction.
(d) Acceleration is always opposite to velocity.

Question 8.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): An object moving at high speed can have zero acceleration.
Reason (R): Acceleration depends on the rate of change of velocity, not on the magnitude of velocity.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

Question 9.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): The magnitude of displacement can never be greater than the total distance travelle(d) Reason (R): Displacement is the shortest path between two points, while distance is the actual path length.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

Question 10.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): In uniform circular motion, the speed of the object remains constant. Reason (R): The velocity of the object also remains constant,
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

B. State True (T) or False (F).

Question 1.
Displacement of an object can never be zero, if the object has moved.

Question 2.
The speedometer reading is nearly equal to the magnitude of the velocity at an instant.

Question 3.
Average speed depends only on displacement, while average velocity depends only on total distance travelled.

Question 4.
An object moving at constant velocity has zero acceleration.

Question 5.
In uniform circular motion, the speed of the object is constant, but its velocity keeps changing.

C. Fill in the blanks.

Complete the following with a suitable word/ words:
Question 1.
If the net force acting on an object is zero, the object will either remain at rest or move with _______ .

Question 2.
Average velocity = Displacement/ _______.

Question 3.
If a car goes from 10 m s^-1 to 0 m s^-1 in 5 s, its acceleration is _______.

Question 4.
The slope of a position-time graph gives _______.

Question 5.
The distance covered by an object in one revolution of radius ‘R’ is _______.

D. Assign one word to the following.

Question 1.
The fixed point used to describe the position of an object.

Question 2.
The quantity that tells us how fast an object moves without giving direction.

Question 3.
Motion in which the direction of velocity changes continuously while speed stays constant.

Question 4.
The physical quantity whose SI unit is m s^-2.

Question 5.
The type of motion represented by a straight-line position-time graph.

E. Match the Column I with Column II.

Question 1.

Column I	Column II
(i) Uniform motion	(a) Meter per second square
(ii) Slope of velocity-time graph	(b) Displacement
(iii) Area under velocity-time graph	(c) Constant speed, Changing direction
(iv) SI unit of acceleration	(d) Acceleration
(v) Uniform circular motion	(e) Straight line (distance-time graph)

F. Very Short Answer Type Questions

Question 1.
Distinguish between uniform and non-uniform motion with one example of each.

Question 2.
During a road trip, Ramesh drives 150 km east in 2 hours, then 90 km west in 1.5 hours. Calculate his average speed and average velocity.

Question 3.
Write the three kinematic equations for motion in a straight line with constant acceleration.

G. Short Answer Type Questions

Question 1.
A train starts from rest and accelerates uniformly. After 30 seconds it reaches a speed of 54 km/h. Calculate, (a) the acceleration, (b) the distance covered in this time.

Question 2.
During a road trip, a man drives 200 km north in 3 hours and then 200 km south in 2 hours. Calculate the average speed and average velocity for the entire trip.

Question 3.
An object is dropped from rest. Using the experimental data (v = 9.8 m s^-1 at t = 1 s; v = 19.6 m s^-1 at t- 2 s; v = 29.4 m s^-1 at t = 3 s, etc.), show that the acceleration due to gravity is constant and determine its value.

H. Long Answer Type Questions

Question 1.
A train starts from rest and accelerates uniformly. After 30 seconds, it reaches a speed of 54 km/h.
Calculate: (i) the acceleration, (ii) the distance covered in this time.

Question 2.
Derive the kinematic equation v² = u² + 2as from the velocity-time graph for an object moving with constant acceleration.

Question 3.
The velocity-time graph from 0 s to 120 s for a cyclist is shown below. Shade the areas (in different colours) representing the displacement of the cyclist (i) while cyclist is moving with constant velocity, (ii) when the velocity of cyclist is decreasing. Also, calculate the displacement and average acceleration in the 120 s time interval.

Wonder Why

A. Give reasons for the following.
Question 1.
A car can be moving at high speed yet have zero acceleration.

Question 2.
The displacement of Sarang is zero after swimming to the other end and back, even though he has covered 50 m.

Question 3.
It is important to maintain a safe distance from the vehicle ahead while driving on the road.

Question 4.
Fuel consumption of a vehicle depends on total distance travelled, not displacement.

Question 5.
A girl is sitting on a merry-go-round. She moves with constant speed along the circular path. Yet, she is said to be accelerating.

Learn By Doing

A. Label the following diagrams.
Question 1.
A skydiver jumps out of a hot-air balloon, which is 4000 m above the ground. At time = 30s, she opens her parachute. The graph is the speed-time graph of her fall.
a. Label with the letter X, the point on the graph where the sky-diver opens her parachute.
b. Label with the letters Y and Z, the two points of the graph where the sky diver falls at a minimum velocity.

Question 2.
Study the velocity-time graph and shade (in different colours) the region showing: (a) displacement during constant velocity phase, and (b) displacement during deceleration phase. Also calculate the total . displacement and the average acceleration in the given time interval.

B. Observe and record.
The table below shows position-time data for two vehicles A and B. Study the data and answer the questions below.

1. Calculate the velocity of vehicle A at any interval of time. Is it uniform?
2. Does vehicle B show uniform or non-uniform motion? How do you conclude?

C. Observe and calculate.

Question 1.
Refer to the position-time graph provided below, which illustrates the motion of an object over a 16 seconds interval. The motion is divided into four distinct regions: A, B, C, and D.

Identify the type of motion in the region A, B, C and D and justify your answer.

Explore With Curiosity

A. A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement-time graph is shown. Plot a velocity-time graph for the same.

B. Analyse and answer.
Question 1.
A motorbike has an initial velocity of 28 m s^-1 and stops after travelling 98 m with constant deceleration. Find: (a) the acceleration, and (b) the time taken to stop.

Question 2.
A bus travelling at 36 km h^-1 sees an obstacle 30 m ahead. The driver takes 0.5 s to react before braking. The brakes cause a deceleration of 2.5 m s^-2. Will the bus stop on time?

Question 3.
A merry-go-round of radius 3 m completes one revolution in 6 s. Calculate: (a) the distance covered in one revolution, and (b) the displacement after one revolution.

C. Read the following passage and answer the questions below.
Meera is driving on a highway at 108 km h^-1. She notices a broken-down vehicle 200 m ahead. Her reaction time is 0.8 s before she presses the brakes. Once the brakes are applied, the car decelerates at 6 m s^-2. A vehicle- to-vehicle (V2V) communication system in her car had already alerted her 3 seconds earlier, giving her extra time to slow down to 72 km h^-1 before she noticed the obstacle visually.

Question 1.
Without the V2V alert, how far does Meera travel during her reaction time?

Question 2.
Without the V2V alert, calculate the total stopping distance (reaction distance + braking distance). Would she stop on time?

Question 3.
With the V2V alert, she slows to 72 km h^-1 first. Recalculate the total stopping distance. How does the V2V system help?

Question 4.
What is the role of velocity in determining stopping distance? Use your calculations to justify.

Suggested Activities

A. Install the Phyphox app on a smartphone. Open ‘Accelerometer (without g)’. Record readings when (a) the phone is on a flat palm, and (b) when you walk holding the phone. Compare the graphs. What do the readings tell you about motion and acceleration in real life? Write your observations below.

B. Create a cardboard disc (radius = 8 cm). Write numbers 1-12 at a distance of 7 cm from the centre and letters A-F at 4 cm from the centre. Spin it at different speeds. Observe that, at certain speeds, the numbers appear blurred but letters remain visible. Calculate and compare the speeds of the numbers and letters. Explain your findings using the concept of uniform circular motion.

C. Talk to a vehicle driver or motor mechanic about factors that affect stopping distance such as wet roads, worn tyres, reaction time, vehicle load, weather conditions. Using your knowledge of kinematic equations, design a safety poster for your school explaining how speed affects stopping distance. Describe the design and key messages of your poster.

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Tissues in Action Class 9 Worksheet with Answers Science Chapter 3

Our subject specific Class 9 Science Worksheet and Class 9 Science Exploration Chapter 3 Tissues in Action Worksheet with Answers Pdf are aligned with latest patterns.

Class 9 Tissues in Action Worksheet

Worksheet On Tissues in Action Class 9

Tissues in Action Worksheet Class 9

→ Tissue: A group of similar cells working together to perform a specific function.

→ Meristematic Tissue: Actively dividing plant tissue responsible for growth in different parts of the plant.

→ Apical Meristem: Tissue located at the tips of roots and shoots that increases the length of the plant.

→ Lateral Meristem: Tissue located on the sides of stems and roots that increases their thickness (girth).

→ Intercalary Meristem: Tissue located at the base of an internode or just above a node that helps plants regrow after cutting or grazing.

→ Differentiation: The process by which meristematic cells become specialised and form permanent tissues.

→ Permanent Tissue: Plant tissue made of cells that have lost the ability to divide and have become specialised to perform specific functions.

→ Epidermis: The outer protective layer of a plant.

→ Cuticle: A waxy layer of cutin covering the epidermis that reduces water loss and protects the plant.

→ Transpiration: Loss of water vapour from plants through stomat(a)

→ Stomata: Tiny pores on the surface of leaves that help in gaseous exchange and transpiration.

→ Transpiration pull: The pulling force created by transpiration that helps in the upward movement of water from roots to leaves through the xylem.

→ Supporting Tissues: Plant tissues that provide mechanical strength, support, and shape to the plant (e.g., parenchyma, collenchyma, sclerenchyma).

→ Parenchyma: A simple living plant tissue with thin walls that mainly stores food and helps in photosynthesis.

→ Tissue: A group of similar cells working together to perform a specific function.

→ Meristematic Tissue: Actively dividing plant tissue responsible for growth in different parts of the plant.

→ Apical Meristem: Tissue located at the tips of roots and shoots that increases the length of the plant.

→ Lateral Meristem: Tissue located on the sides of stems and roots that increases their thickness (girth).

→ Intercalary Meristem: Tissue located at the base of an internode or just above a node that helps plants regrow after cutting or grazing.

→ Differentiation: The process by which meristematic cells become specialised and form permanent tissues.

→ Permanent Tissue: Plant tissue made of cells that have lost the ability to divide and have become specialised to perform specific functions.

→ Epidermis: The outer protective layer of a plant.

→ Cuticle: A waxy layer of cutin covering the epidermis that reduces water loss and protects the plant.

→ Transpiration: Loss of water vapour from plants through stomat(a)

→ Stomata: Tiny pores on the surface of leaves that help in gaseous exchange and transpiration.

→ Transpiration pull: The pulling force created by transpiration that helps in the upward movement of water from roots to leaves through the xylem.

→ Supporting Tissues: Plant tissues that provide mechanical strength, support, and shape to the plant (e.g., parenchyma, collenchyma, sclerenchyma).

→ Parenchyma: A simple living plant tissue with thin walls that mainly stores food and helps in photosynthesis.

→ Collenchyma: Living tissue that provides flexibility and allows plant parts to bend without breaking.

→ Pectin: A natural chemical substance present in plant cell walls that thickens the corners of collenchyma cells and provides flexibility like rubber.

→ Sclerenchyma: A simple plant tissue made of dead cells with very thick, lignin-filled walls that make it hard and strong, found in stems, leaf veins, and hard seed and nut coverings.

→ Lignin: A hard chemical substance in plant cell walls that makes them strong, rigid, and woody.

→ Conducting Tissues: Complex plant tissues that transport water, minerals, and food throughout the plant (xylem and phloem).

→ Xylem: Tissue that transports water and minerals from roots to other parts of the plant.

→ Phloem: Tissue that transports food from leaves to all parts of the plant.

→ Sieve Tubes: Long, tube-like cells in phloem that transport food (sugars) in plants.

→ Companion Cells: Cells associated with sieve tubes that help in the loading and unloading of food. Dermal Tissue System: The outer protective covering of a plant that reduces water loss.

→ Ground Tissue System: The tissue forming the main body of the plant between dermal and conducting tissues.

→ Vascular Tissue System: The conducting tissue system made up of xylem and phloem.

→ Epithelial Tissue: Tissue that forms the outer covering of the body and lines internal organs. Connective Tissue: Tissue that connects and supports other tissues of the body.

→ Blood: A fluid connective tissue containing plasma, RBCs, WBCs, and platelets.

→ Bone: A hard, strong connective tissue forming the body’s framework.

→ Tendon: Connective tissue that joins muscles to bones.

→ Cartilage: A soft connective tissue that provides flexibility and cushioning.

→ Ligament: Connective tissue that joins bones to bones and limits movement.

→ Matrix: The material present between cells in connective tissue.

→ Muscular Tissue: Tissue that helps in the movement of body parts.

→ Voluntary Movement: Movement under conscious control.

→ Involuntary Movement: Movement that occurs automatically.

→ Skeletal Muscles: Muscles attached to bones that help in voluntary movements.

→ Smooth Muscles: Involuntary, non-striated muscles that control slow movements in internal organs.

→ Cardiac Muscles: Involuntary, striated muscles of the heart that contract rhythmically without fatigue. Nervous Tissue: Tissue that controls and coordinates body activities.

→ Neuron: A nerve cell that transmits messages.

→ Cell Body: The part of a neuron that contains the nucleus and controls cell activities.

→ Dendrites: Branch-like structures that receive signals from other neurons.

→ Axon: A long fibre that carries messages away from the cell body to axon terminals, which transmit messages to other cells.

→ Musculoskeletal System: System made up of bones, muscles, joints, tendons and ligaments that helps in movement and support.

→ Joint: Junction between two or more bones.

→ Ball-and-Socket Joint: Joint that allows movement in all directions (shoulder, hip).

→ Hinge Joint: Joint allowing movement in one direction only (elbow, knee).

→ Pivot Joint: Joint allowing rotational movement (neck).

→ Fixed Joint: Immovable joint providing protection (skull).

→ Skeletal System: Framework of bones that gives shape, support and protection to the body.

→ Backbone or Vertebral Column: A series of vertebrae that support the body, enable movement, and provide flexibility with cushioning discs.

→ Vertebrae: Small bones that make up the backbone.

Class 9 Science Exploration Chapter 3 Worksheet

Class 9 Science Tissues in Action Worksheet

A. Multiple-Choice Questions

Question 1.
If companion cells are damaged, what will be the immediate effect on the plant?
(a) Water transport will stop.
(b) Sugar transport in sieve tubes will be affected
(c) Photosynthesis will stop.
(d) Mechanical strength will decrease.

Question 2.
When you touch a hot object and quickly pull your hand away, which tissue is mainly responsible?
(a) Muscular tissue I
(b) Epithelial tissue
(c) Nervous tissue
(d) Connective tissue I

Question 3.
Why are ribs joined by cartilage?
(a) To make them hard
(b) To allow flexibility
(c) To increase weight
(d) To store minerals

Question 4.
Which part of the plant creates the pulling force for water movement?
(a) Roots
(b) Stem
(c) Leaves
(d) Flowers

Question 5.
Identify the correct statements about the tissue shown in the figure.

(a) Its main function is storage of food.
(b) It also performs photosynthesis in the green parts of the plants.
(c) It has thickened corners due to pectin deposition.
(d) Both a and b

Question 6.
Which statement correctly explains why meristematic cells lack vacuoles?
(a) They store excess water.
(b) They need space for cell division.
(c) They are dead cells.
(d) They perform photosynthesis.

Question 7.
Coconut husk fibres are hard and brittle mainly because they contain
(a) parenchyma cells
(b) collenchyma cells
(c) sclerenchyma cells
(d) epidermal cells.

Question 8.
Poses of Surya Namaskar protect the body from
(a) growth problems
(b) stiffness
(c) digestive problems
(d) breathing problems.

Question 9.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason the appropriate answer.
Assertion (A): Xylem transports food in plants.
Reason (R): Xylem consists of tracheids, vessels, xylem parenchyma and xylem fibres.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

Question 10.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason the appropriate answer.
Assertion (A): Cardiac muscles do not get fatigued easily.
Reason (R): Cardiac muscles work rhythmically throughout life.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

B. State True (T) or False (F).

Question 1.
Meristematic tissues can divide continuously.

Question 2.
Permanent tissues can divide actively.

Question 3.
Sclerenchyma cells are living and flexible.

Question 4.
Cartilage is harder than bone.

Question 5.
Smooth muscles are involuntary.

Question 6.
Nervous tissue helps in coordination and control.

Question 7.
Ball and socket joints allow movement in all directions.

Question 8.
Sipra Guha Mukherjee and S. C. Maheshwari developed a complete plant through anther culture.

C. Fill in the blanks.

Question 1.
Nervous tissue is made up of an organised network of _______ .

Question 2.
Cardiac muscles are specifically found in ______ .

Question 3.
_______ helps in increasing the length of plants.

Question 4.
The outer protective layer of plants is called _______.

Question 5.
The process of becoming specialised is called _______.

Question 6.
Xylem and phloem together form _______tissue system.

Question 7.
Annual rings are found in the _______ of trees.

D. Assign one word to the following.

Question 1.
Junctions between two or more bones that allow movement.

Question 2.
Connect bones to bones and prevent excessive movement.

Question 3.
Growth zones present at the tips of stems and roots.

Question 4.
A waxy layer in cells that reduces water loss and provides protection.

Question 5.
Spindle-shaped, non-striated muscle cells.

Question 6.
Non-flexible skeletal tissue.

E. Match the Columns.

Question 1.
Match the types of plant tissues given in Column I with their characteristics listed in Column II.

Column I	Column II
(i) Parenchyma	(a) Provides mechanical strength and flexibility
(ii) Collenchyma	(b) involved in photosynthesis and storage
(iii) Sclerenchyma	(c) Transports food in plants
(iv) Xylem	(d) Consists of dead cells with thickened walls

Question 2.
Match the images of the types of epithelial tissues given in Column I with their structural descriptions listed in Column II.

F. Identify whether the following muscles represent voluntary or involuntary movements, and match them accordingly.

G. Very Short Answer Type Questions

Question 1.
What is the function of stomata?

Question 2.
Name the part of the phloem with perforated walls.

Question 3.
What are vertebrae?

H. Short Answer Type Questions

Question 1.
Why are some annual rings wide and some narrow?

Question 2.
How will you identify cardiac muscles cells under a microscope?

Question 3.
What is the role of joints in the body?

I. Long Answer Type Questions

Question 1.
Explain permanent tissues and the process of differentiation.

Question 2.
Differentiate between bone and cartilage.

Question 3.
(i) Identify and name the structure shown in the given figure.

(ii) Name the parts labelled A to E.

(iii) Explain how this structure works.

Wonder Way

A. Give reasons for the following.

Question 1.
Neurons are long cells.

Question 2.
Muscles are necessary for the movement of bones.

Question 3.
Cartilage provides flexibility at joints.

Question 4.
Epithelial tissue forms a protective covering.

Question 5.
Fixed joints do not allow movement.

Question 6.
Xylem vessels are tubular in structure.

Question 7.
Smooth muscles are involuntary.

Question 8.
Grass appears after some time after being mowed or grazed by animals.

Question 9.
Aquatic plants float easily, while dry twigs break more easily compared to fresh ones.

Question 10.
Stem cells from a healthy person are used in bone marrow transplants to treat diseases like leukaemia and thalassemi(a)

B. Read the paragraph and answer the following questions.
Rohan was playing cricket when he accidentally got hit on the chest by a ball. After the incident, he felt pain while breathing and noticed that it was difficult to take deep breaths. His doctor explained that the ribs form a protective cage around vital organs. He also told Rohan that the ribs are connected to the spine at the back and to the sternum in the front with the help of cartilage.

Question 1.
Why was Rohan finding it difficult to breathe after the injury?

Question 2.
Which vital organs are protected by the rib cage?

Question 3.
Why is the flexibility of the rib cage important for breathing?

C. Some parts of our body can move easily in many directions, while others move only in a single direction. Justify the statement.

Learn By Doing

A. Observe a small plant or hedge in your surroundings and, if possible, trim the tip of a young stem under adult supervision. Over the next few days, note the changes in its growth, especially whether the growth in length stops and new branches begin to grow from the nodes. Also, observe grass that regrows after mowing. Based on these observations, identify the types of meristematic tissues responsible for growth in length and regeneration. Finally, think about the structure of meristematic cells and explain why they lack vacuoles and how this helps in rapid cell division.

Look at the given diagram and answer the following questions.

Question 1.
Identify and name the structure shown in the given figure.

Question 2.
Name the parts labelled P to U.

Question 3.
Give two examples of daily activities where part T helps in body movement

C. Identify diagrams (i) and (ii) and name the parts labelled in each. Also, explain how you identified each one, giving at least two reasons in the space given below.

D. Complete the flowchart given below:

Explore With Curiosity

A. Rlya and her classmates performed an experiment to study the growth of onion roots. They took two jars, A and B, and placed onion bulbs in water. In Jar A, the roots were left undisturbed, while in Jar B, the root tips were carefully cut after 4 days. They measured the length of the roots every day for 7 days and plotted a graph.

Now, answer the following questions.

Question 1.
What difference do you observe in the growth pattern of Jar A and Jar B?

Question 2.
Why did the roots in Jar A continue to grow?

Question 3.
What caused the roots in Jar B to stop growing after Day 4?

Question 4.
Which type of plant tissue is responsible for root growth?

B. While visiting a farm, Neha noticed some plants with unusual swollen growths on their stems. Worried, she asked the farmer about it. The farmer told her it was a disease, but also mentioned that scientists study such diseases to learn something useful.

Now, answer the following questions:
1. Why do plants develop tumour-like swellings in crown gall disease?
2. Why do scientists study plant diseases like the one Neha observed, and how can such studies be useful for improving plants?

C. Observe the given activities and write the names of the joints involved in each activity in the given table.

Suggested Activities

A. Visit a doctor, physiotherapist, or sports trainer and find out about ligament rupture, cartilage damage, and bone fractures. Prepare a short report on what causes these injuries and how they are treate(d) Also suggest lifestyle changes such as regular exercise, maintaining correct posture, and consuming calcium- and protein-rich foods to reduce the risk of such injuries.

B. Observe gardening practices like pruning, grafting, irrigation, and crop rotation. Explain how each method supports plant tissues, including meristems (for growth), conducting tissues (for transport), and supporting tissues (for strength). You may also draw labelled diagrams of plants showing these effects.

C. Learn five basic steps from any tribal or traditional dance form. Observe which joints (shoulder, elbow, knee, ankle) are used in each movement. Create a short dance or drama that shows how joints help in smooth body movement, and perform it in class or at a school assembly.

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Cell The Building Block of Life Class 9 Worksheet with Answers Science Chapter 2

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Class 9 Cell The Building Block of Life Worksheet

Worksheet On Cell The Building Block of Life Class 9

Cell The Building Block of Life Worksheet Class 9

→ Cell: The basic structural and functional unit of life.

→ Thermophile: Heat-loving microorganisms that live in extreme hot environments like hot springs.

→ Palaeoscience: The branch of science that studies ancient life and early Earth conditions using evidence like fossils and mineral deposits.

→ Limit of Resolution: The ability to distinguish two close points as separate; for the human eye, it is about 0.1 mm.

→ Cell Biologists: Scientists who study cells, their structure, functions, and activities.

→ Lens: A curved transparent material that bends light to magnify or make objects appear larger.

→ Magnification: The enlargement of an object’s image using lenses to see fine details.

→ Microscope: An instrument that uses lenses to magnify small objects not visible to the naked eye.

→ Light Microscope: A microscope that uses light to magnify objects.

→ Electron Microscope: A powerful microscope that uses a beam of electrons instead of light to provide very high magnification.

→ Cell Membrane (Plasma Membrane): A thin, selectively permeable boundary that controls the movement of substances in and out of the cell.

→ Selectively Permeable: Allowing some substances to pass through while preventing others.

→ Osmosis: Movement of water from higher water concentration to lower water concentration through a selectively permeable membrane.

→ Concentration Gradient: Difference in concentration between two regions.

→ Diffusion: The net movement of particles from higher to lower concentration.

→ Isotonic Solution: A solution with the same solute concentration inside and outside the cell, causing no net movement of water, so the cell size remains the same.

→ Hypotonic Solution: A solution with lower solute concentration outside the cell, causing water to enter the cell and the cell to swell.

→ Hypertonic Solution: A solution with higher solute concentration outside the cell, causing water to move out of the cell and the cell to shrink.

→ Fluid-Mosaic Model: A model that describes the cell membrane as a flexible layer of lipids with proteins embedded in it.

→ Cell Wall: A rigid outer layer surrounding the cell membrane that provides shape, support, and protection to the plant cell.

→ Prokaryotic Cells: Simple cells without a true nucleus and membrane-bound organelles; their genetic material is present in the nucleoid (e.g., bacteria).

→ Eukaryotic Cells: Complex cells with a well-defined nucleus and membrane-bound organelles (e.g., plant and animal cells).

→ Viruses, Viroids, and Prions: Very small infectious agents that do not have cells.

→ Cytoskeleton: A network of protein fibres that provides shape, support, and movement to the cell.

→ Chromatin: A thread-like structure of DNA and proteins present in the nucleus that condenses to form chromosomes during cell division.

→ Nucleoid: The region in prokaryotic cells where genetic material is present without a nuclear membrane.

→ Cristae: Finger-like projections of the inner membrane of mitochondria that increase the surface area for chemical reactions and help in energy production.

→ Plastids: Double-membrane organelles found in plant cells that are involved in food synthesis, storage, and imparting colour to plants.

→ Stroma: The semi-fluid substance inside the chloroplast where sugars synthesised during photosynthesis are stored along with starch granules.

→ Cell Sap: The liquid inside the vacuole that stores water, nutrients, and wastes.

→ Cell Division: The process by which new cells are formed from existing cells.

→ Cell Cycle: A controlled and orderly series of events in eukaryotic cells leading to cell division.

→ Mitosis: Cell division producing two identical daughter cells for growth and repair.

→ Meiosis: Cell division producing four daughter cells with half the number of chromosomes of the parent cell; it helps in sexual reproduction and creates variation.

→ Cell Culture: The process of growing cells outside a living organism in a controlled laboratory environment.

→ Vaccine: A substance that helps the body develop immunity against a disease.

→ Totipotency: The ability of a single cell to develop into a complete organism under suitable conditions.

→ Contact Inhibition: Property of normal cells to stop dividing when they touch neighbouring cells.

→ Tumour: Abnormal mass of cells formed due to uncontrolled cell division.

→ Cancer: Disease caused by uncontrolled cell division.

→ Programmed Cell Death (PCD): Natural and controlled process in which a cell intentionally dies as part of growth, development, or maintaining balance within an organism.

Class 9 Science Exploration Chapter 2 Worksheet

Class 9 Science Cell The Building Block of Life Worksheet

A. Multiple-Choice Questions

Question 1.
Which of the following can be seen only with the help of an electron microscope?
(a) Nucleus
(b) Ribosomes
(c) Fish egg
(d) Mitochondria

Question 2.
The limit of resolution of the human eye is
(a) 2.5 mm
(b) 0.25 mm
(c) 0.01 mm
(d) 0.1 mm

Question 3.
Which of the following characteristics classify bacterial cells as prokaryotic?
(a) They lack a well-defined nucleus.
(b) They have large vacuoles,
(c) They contain chloroplasts.
(d) They are multicellular.

Question 4.
forms a network of fine fibres, providing structural support, maintains cell shape, and cell movement in eukaryotes.
(a) Cytoskeleton
(b) Leucoplasts
(c) Nucleus
(d) Vacuole

Question 5.
Which option correctly identifies the structures labelled X and Y in the given diagram of the nucleus?

(a) X – Nucleolus; Y – Chromatin
(b) X – Chromatin; Y-Nucleolus
(c) X – Nuclear pore; Y- Nucleolus
(d) X – Chromatin; Y- Nuclear pore

Question 6.
Which statement correctly differentiates mitosis and meiosis?
(a) Mitosis produces four daughter cells, while meiosis produces two daughter cells.
(b) Mitosis occurs only in reproductive organs, while meiosis occurs in all body cells.
(c) Mitosis produces genetically identical daughter cells, while meiosis produces genetically different daughter cells.
(d) Mitosis reduces chromosome number by half, while meiosis maintains the same number of chromosomes.

Question 7.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): All plastids contain chlorophyll.
Reason (R): Chromoplasts give colour to flowers.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

Question 8.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): Cancer cells form tumours.
Reason (R): Cancer cells show contact inhibition.?
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

B. State True (T) or False (F).

Question 1.
Prokaryotes do not have a membrane-bound nucleus.

Question 2.
Chromoplasts are present in potatoes that make it colourless.

Question 3.
Viroids have a protein coat.

Question 4.
Mitosis produces two identical daughter cells.

Question 5.
The cell wall prevents plasmolysis.

Question 6.
Chromatin condenses into chromosomes during division.

Question 7.
Vacuoles are larger in animal cells.

C. Fill in the blanks.

Question 1.
Arun Kumar Sharma was an Indian scientist famous for his work on ______.

Question 2.
______ is the energy currency of the cell.

Question 3.
Starch and crystals of calcium oxalate or silica in plant cells are known as _______.

Question 4.
________ is involved in synthesis and storage of fats and hormones.

Question 5.
Errors in _______ lead to uncontrolled cell divisions, while errors in ______ may result in genetic disorders.

Question 6.
Movement of water from higher to lower concentration through a semi-permeable membrane is called ______

D. Assign one word to the following.

Question 1.
The process that creates genetic diversity in gametes.

Question 2.
Genetically regulated and organised process of selective cell destruction.

Question 3.
The process by which new cells form from pre-existing cells.

Question 4.
Genetic region without a nuclear membrane in bacteria.

Question 5.
Organelles that act as waste digesters.

Question 6.
The process that prevents uncontrolled division in normal cells.

Question 7.
Heat-loving bacteria in hot springs.

Question 8.
Net movement of particles from a higher to a lower concentration.

Question 9.
Fluid-mosaic structure that is selectively permeable and allows movement of water through osmosis.

Question 10.
Solution that causes a potato piece to shrink.?

E. Match the Columns.

Question 1
Match the diagrams given in Column I with the terms given in Column II.
Column I

Question 2.
Match the Column I with Column II

Column I	Column II
(i) Mitosis	(a) Genetic diversity
(ii) Meiosis	(b) Identical daughter cells
(iii) Gene	(c) Visible during division
(iv) Chromosome	(d) Functional segment of DNA

F. Differentiate between the following.

Question 1.
Differentiate between the Nucleus and Nucleolus

Question 2.
Differentiate between the Cell Membrane and Nuclear Membrane

Question 3.
Differentiate between the Hypertonic Solution and Hypotonic Solution

G. Write the correct biological term for each description.

Question 1.
Powerhouse of the cell

Question 2.
Packaging and shipping centre of the cell

Question 3.
Manufacturing factory of the cell

Question 4.
House of coded instructions of the cell

Question 5.
Protein factory of the cell

Question 6.
The clean-up system of the cell

H. Very Short Answer Type Questions

Question 1.
Name the scientists who proposed the cell theory.

Question 2.
Write the full form of DNA.

Question 3.
What is the near point of human eye?

I. Short Answer Type Questions

Question 1.
Write a short note on the discovery of cells by Robert Hooke.

Question 2.
Why do errors in meiosis affect offspring more severely than errors in mitosis?

Question 3.
Write a short note on the Endoplasmic Reticulum.

J. Long Answer Type Questions

Question 1.
Describe meiosis in detail with the help of a diagram.

Question 2.
Explain the differences between plant and animal cells with examples.

Question 3.
Briefly describe the three basic parts of a eukaryotic cell.

Wonder Why

A. Read the paragraph and answer the following questions.
Amit wondered why pancreatic cells appeared different under an electron microscope. His teacher explained that these cells contain abundant rough endoplasmic reticulum (RER) with attached ribosomes for protein synthesis, while liver cells have more smooth endoplasmic reticulum (SER) for lipid synthesis. Both cell types contain mitochondria with cristae folds to generate ATP. These cells also contain Golgi apparatus, which plays an important role in processing materials inside the cell. The teacher emphasised that this precise “cellular factory” coordination is absent in prokaryotes, which lack membrane-bound organelles.

Question 1.
Why are pancreatic cells rich in RER?

Question 2.
What makes RER appear rough under the microscope?

Question 3.
How does the Golgi apparatus help these cells in protein transport and secretion??

Question 4.
Why can prokaryotes not specialise like pancreatic cells?

B. Give reasons for the following. Interpret/Analyse

Question 1.
The presence of cristae on the inner membrane of mitochondria.

Question 2.
The Golgi apparatus is known as the packaging and shipping centre.

Question 3.
Eukaryotes need the Golgi after RER, unlike prokaryotes.

Question 4.
Chromoplasts in petals evolved despite no photosynthetic role.

Question 5.
Human cheek cells shrink more than Rhoeo peels in hypertonic sugar.

Question 6.
Prokaryotic thermophiles survive in Ladakh hot springs while complex eukaryotes cannot.

C. Observe the images. Identify and write the names of cells.

Now, answer the following questions.
Question 1.
What will happen if B cells are kept in a hypotonic solution? Why?

Question 2.
What will happen if A cells are kept in a hypertonic solution? Why?

D. A scientist observed that a fully mature plant cell can give rise to an entire plant in laboratory conditions. Explain the concept behind this property of plant cells.

E. How does Programmed Cell Death help in shaping the human body during development?

Learn By Doing

A. Take three glasses— (I) one with plain water, (II) one with concentrated sugar/salt solution, and (III) one with a dilute solution sugar/salt solution. Place equal-sized pieces of carrot in each glass for about 1 hour. Observe the changes and label the setups correctly as hypotonic, hypertonic and isotonic solution.

Now, answer the following questions based on your observation.

Question 1.
What changes do you observe in the carrot pieces in each solution?

Question 2.
Which solution makes the carrot piece firm and why?

Question 3.
Which solution makes the carrot piece soft or shrunken and why?

B. Give two examples of the following situations.

Question 1.
Cells that undergo meiosis

Question 2.
Cells lacking cell wall

Question 3.
Single membrane organelles

Question 4.
Hypertonic solutions

Question 5.
Unicellular organisms

Question 6.
Plants having leucoplast

C. Observe the given image carefully, and answer the following questions.

Question 1.
What does the given image represent?

Question 2.
State the importance of this type of division.

Question 3.
What happens to the chromosome number after this division?

Question 4.
Briefly describe the steps involved in preparing and observing this stage under a microscope.

Explore With Curiosity

A. Using the microscope in your school laboratory, identify and label the parts shown in the given image. Then, carefully observe and handle the microscope to understand the function of each part while focusing on a slide, and record the use of each part in your notebook.

B. What would happen if

Question 1.
The lysosomes disappeared completely from the cell.

Question 2.
The plasma membrane became impermeable.

Question 3.
You put a freshwater fish in seawater.

Question 4.
Mitochondria stopped producing ATP for the cell.

C. A scientist was studying cells using a simple microscope and could observe only basic structures like the nucleus and cell boundary. However, many tiny internal structures remained invisible. Later, the scientist started using an advanced
instrument, as shown in the image below, and was able to observe very fine details inside the cell.

While preparing onion peel and human cheek cell slides, the scientist observed that without adding a stain, the cells appeared nearly transparent. After staining, certain structures became much more distinct than others.

Observe and analyse the situation, then answer the following questions.
Question 1.
Name the advanced instrument that the scientist use(d)

Question 2.
Why is staining necessary for observing onion peel and cheek cells?

Question 3.
Why was the scientist unable to see certain structures with a simple microscope?

Question 4.
How did the advanced instrument help in observing more details inside the cell?

Suggested Activities

A. To compare prokaryotic and eukaryotic cells, collect yoghurt (prokaryotic bacteria) and onion peels (eukaryotic plant cells). Prepare wet mounts of both samples and observe under a microscope, noting size differences, the presence of a nucleus, and organelle visibility. Sketch your observations, measure relative sizes using microscope. Create a comparison table showing how prokaryotic cells are smaller and simpler, while eukaryotic cells are larger and more complex. Discuss why prokaryotic cells can divide faster due to their simple structure.

B. Design and prepare a three-dimensional model of a cell using low-cost, eco-friendly materials. Clearly show and label important cell parts such as the cell membrane, cytoplasm, nucleus, and other organelles. Explain the function of each part and present the model neatly and creatively.

C. Visit a plant nursery or botanical garden and ask growers about wilting prevention. Collect leaf samples from turgid/wilted plants, prepare temporary slides of leaf peel, and observe vacuole shrinkage under a microscope. Research how cell wall rigidity supports osmosis in plants compared to flexibility in animal cells.

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Exploration Entering the World of Secondary Science Class 9 Worksheet with Answers Science Chapter 1

Our subject specific Class 9 Science Worksheet and Class 9 Science Exploration Chapter 1 Exploration Entering the World of Secondary Science Worksheet with Answers Pdf are aligned with latest patterns.

Class 9 Exploration Entering the World of Secondary Science Worksheet

Worksheet On Exploration Entering the World of Secondary Science Class 9

Exploration Entering the World of Secondary Science Worksheet Class 9

→ Exploration: A systematic and purposeful process of observing, questioning, and understanding the natural world.

→ Experiment: A planned procedure carried out to test a hypothesis or idea.

→ Measurement: The process of quantifying observations using standard units.

→ Symbols: The short representations (like m, v, F, I) used to denote physical quantities such as mass, velocity, force and electric current.

→ Equation: An equation is a compact statement about how certain things are related.

→ Model: A simplified representation of a real system used to understand complex phenomena.

→ Scientific Idea: An explanation or concept developed through observation and experimentation.

→ Air Resistance: The force exerted by air that opposes the motion of a moving object.

→ Standard Units (SI Units): Internationally accepted units used for consistent and accurate measurements.

→ Law: A regular pattern observed in nature, often expressed using words or mathematically.

→ Theory: An explanation of why certain patterns or events occur, based on evidence gathered over time.

→ Evidence: The data or information collected through observation and experiments that support a conclusion.

→ Principle: A broad scientific idea that is applied to explain or predict situations.

→ Prediction: A reasoned conclusion about future events based on scientific knowledge and evidence.

→ Chemical Reactions: The processes in which substances change into new substances with different properties. Biological

→ Principles: The basic concepts and rules that explain how living organisms function and interact. Scientific Theory: A well-tested explanation of natural phenomena based on evidence and repeated testing.

→ Pandemic: A disease outbreak that spreads across many countries or continents and affects a large number of people, for example, COVID-19.

→ Scientific Thinking: A way of thinking that involves logical reasoning, questioning, and reliance on evidence.

→ Estimation: The process of finding an approximate value when exact measurement is not necessary.

Class 9 Science Exploration Chapter 1 Worksheet

Class 9 Science Exploration Entering the World of Secondary Science Worksheet

A. Multiple-Choice Questions

Question 1.
Which statement best describes ‘Science’?
(a) Science removes all types of uncertainties.
(b) Science reduces uncertainties through evidence.
(c) Science depends only on fixed rules.
(d) Science avoids calculations and logical reasoning.

Question 2.
Standard units are important because they
(a) simplify models
(b) remove the need for experiments
(c) ensure consistency in measurements
(d) replace reasoning.

Question 3.
Which of the following is not a part of the scientific process?
(a) Observation
(b) Evidence-based reasoning
(c) Prediction based only on personal belief
(d) Measurement

Question 4.
Models are used to
(a) add more details
(b) simplify complex systems
(c) replace experiments
(d) avoid logical thinking.

Question 5.
A scientific theory is
(a) a random opinion
(b) a law
(c) a well-tested explanation
(d) a fixed unit of measurement.

Question 6.
Which of the following estimates is most reasonable for the mass of a school bag?
(a) 2 mg
(b) 5 kg
(c) 500 kg
(d) 50 tonnes

Question 7.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): Mathematics is essential in science.
Reason (R): Mathematics helps express relationships clearly.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

Question 8.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): A scientific theory explains why certain patterns occur based on evidence gathered over time. Reason: Principles are broad ideas that help us understand and apply concepts in specific situations.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

B. State True (T) or False (F).

Question 1.
If something cannot be measured, it cannot be studied scientifically.

Question 2.
A model with more assumptions is always less reliable.

Question 3.
Pounds and kilograms are different units of measurements.

Question 4.
Scientific reasoning involves the interpretation of evidence.

Question 5.
Scientific laws never change.

Question 6.
Mathematics can be used to model airflow and filtration efficiency in masks.

C. Fill in the blanks.

Question 1.
_______ helps express relationships between quantities.

Question 2.
Units used worldwide are called ______ units.

Question 3.
A ______ describes a regular pattern in nature.

Question 4.
A ______ explains why something happens.

Question 5.
_______ gives approximate values.

D. Assign one word to the following.

Question 1.
A systematic way of understanding the world through observation, experimentation, and reasoning.

Question 2.
The Latin word from which the symbol ‘c’ for the speed of light is derived

Question 3.
The physicist who explained how the colour of stars is connected to their temperature.

E. Match Column I with Column II.

Column I	Column II
(i) Model	(a) Describes a pattern
(ii) Scientific Law	(b) Approximate calculation to check reasonableness
(iii) Scientific Theory	(c) Quantifies observation
(iv) Measurement	(d) Explains pattern
(v) Estimation	(e) Simplified representation of a system

F. Differentiate between the following.
Question 1.
Differentiate between Law and Theory

G. Very Short Answer Type Questions

Question 1.
Is the statement “All scientific ideas are final and cannot be changed” correct?

Question 2.
In science, what is a ‘theory’?

Question 3.
What helps scientists make predictions?

H. Short Answer Type Questions

Question 1.
A student says, “Science is just a collection of facts.” Do you agree? Justify your answer.

Question 2.
How are scientific ideas tested and improved?

Question 3.
How does the use of standard units make science reliable?

I. Long Answer Type Questions

Question 1.
Describe the process of scientific exploration.

Question 2.
Explain how failure of a prediction can actually help scientific progress using a suitable example.

Wonder Way

A. Read the following paragraph and answer the following questions.
Rohan was watching a cricket match and wondered whether the ball would go for a six. His friend said, “We should consider everything — colour of the ball, grass on the field, crowd noise, and even the colour of the player’s jersey.”
Rohan disagreed and said that only a few factors really matter for predicting the motion of the ball.

Question 1.
Why does Rohan think that considering every detail is not useful for predicting the motion of the ball?

Question 2.
Identify any two important factors that should be considered while predicting the motion of the ball.

Question 3.
List any two factors that can be ignored in this situation.

B. Give reasons for the following.

Question 1.
Two scientists using the same data may arrive at different conclusions.

Question 2.
Scientific laws can change over time.

Question 3.
‘Kilogram’ is considered a standard unit across the worl(d)

Question 4.
Food does not become harmful during an eclipse.

Question 5.
Approximate reasoning is an important scientific skill.

Learn By Doing

A. A student tries to create a model to study the motion of a car. She includes every detail—engine structure, tyre friction, air resistance, driver behaviour, road texture, and even weather conditions. As a result, her model becomes too complex to analyse.

Question 1.
What mistake did the student make?

Question 2.
Why are simpler models often more useful?

Question 3.
If air resistance is ignored, does the model become completely wrong?

B. Riya usually takes 20 minutes to reach school. One day, it starts raining heavily. She predicts that she will still reach school in 20 minutes, assuming that her speed and travel conditions will remain unchange(d) However, she actually takes 35 minutes to reach school.

Question 1.
Analyse why Riya’s prediction faile(d) Which assumptions were unrealistic under rainy conditions?

Question 2.
Identify the factors that would most significantly affect her travel time in the rain.

Question 3.
Propose an improved way to predict travel time on rainy days. Explain what changes you would make and why they would increase accuracy.

Explore with Curiosity

A. Reema tries to predict how long it takes to boil water. She includes room temperature, size of vessel, colour of the vessel, brand of stove, and even the design on the vessel.

Question 1.
What problem might arise from including too many details?

Question 2.
Which one or two factors are most important here?

Question 3.
Why is it useful to ignore some details?

B. A passenger aircraft once faced an emergency landing because of a mix-up in measurement units. The flight required 22,300 kg of fuel, but the ground crew used fuel values in pounds (lb) instead of kilograms ikg). As a result, the aircraft received much less fuel than needed and had to make an emergency landing

Question 1.
What mistake was made by the ground crew?

Question 2.
Why is it important to use standard units (SI) in science and engineering?

Question 3.
What problems can arise from incorrect unit conversions in real-life situations?

Suggested Activities

A. Choose any everyday activity (such as cooking or playing a sport). List the important factors involved and identify the factors that can be ignored while making a simple model.

B. Observe any two products at home that show measurements (such as weight or volume). Record the units used and check whether they follow standard units.

C. Make a prediction about a daily task. Compare it with the actual result and explain any difference observed

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Predicting What Comes Next Exploring Sequences and Progressions Class 9 Worksheet with Answers Maths Chapter 8

Teachers can assign these Ganita Manjari Class 9 Worksheet and NCERT Class 9 Maths Chapter 9 Predicting What Comes Next Exploring Sequences and Progressions Worksheet with Answers Pdf for daily practice.

Predicting What Comes Next Exploring Sequences and Progressions Worksheet Class 9

Class 9 Maths Predicting What Comes Next Exploring Sequences and Progressions Worksheet

Worksheet On Predicting What Comes Next Exploring Sequences and Progressions Class 9

Multiple Choice Questions

Question 1.
If the 2^nd term of an AP is 13 and the 5^th term is 25, what is its 7^th term?
(a) 30
(b) 33
(c) 37
(d) 38
Answer:
(b) 33

Question 2.
If 7 times the 7^th term of an AP is equal to 11 times its 11^th term, then its 18th term will be
(a) 11
(b) 18
(c) O
(d) 7
Answer:
(c) O

Question 3.
The sum of first 8 multiples of 8 is _____ .
(a) 264
(b) 188
(c) 252
(d) 288
Answer:
(d) 288

Question 4.
What is the common difference of an AP in which a₂₀ – a₁₄ = 36?
(a) 5
(b) 6
(c) 8
(d) 9
Answer:
(b) 6

Question 5.
In a GP, each term is obtained by
(a) adding a fixed number
(b) multiplying by a fixed number
(c) subtracting a fixed number
(d) none of these
Answer:
(b) multiplying by a fixed number

Question 6.
Which of the following forms an AP?
(a) 100,90,80,70
(b) \(\frac{1}{2}, \frac{3}{2}, \frac{5}{2}, \frac{7}{2}\)
(c) Both (a) and (b)
(d) None of these
Answer:
(c) Both (a) and (b)

Question 7.
The n^th term of a sequence is given by t_n = 3n². The ratio of the ^rd term to the 2^nd term is ___________.
(a) 2 : 1
(b) 3 : 2
(c) 9 : 4
(d) 1 : 3
Answer:
(c) 9 : 4

Question 8.
A recursive rule generates a sequence where each term increases by 5. If t_n = 20, the first term is _______.
(a) 0
(b) 5
(c) 10
(d) 15
Answer:
(b) 5

Question 9.
A recursive sequence is defined as t₁ = 2, t_n = 3t_n-1 ; n ≥ 2. Which statement is correct?
(a) It is an AP with common ratio 3
(b) It is a GP with common ratio 3
(c) It is neither AP nor GP
(d) It has a common difference
Answer:
(b) It is a GP with common ratio 3

Question 10.
The n^th term of a geometric progression is given by t_n = 2 × (-3)^n-1 ; n ≥ 2. What is the 5^th term of the sequence?
(a) -54
(b) 54
(c) -162
(d) 162
Answer:
(d) 162

Question 11.
The 7^th term of the GP 3, 6, 12, …, is ______.
(a) 48
(b) 192
(c) 96
(d) 144
Answer:
(b) 192

Question 12.
A GP has 3^rd term =12 and 5^th term = 48. The common ratio is ________.
(a) 2
(b) 3
(c) 4
(d) 6
Answer:
(a) 2

Question 13.
Which statement is true about the Virahanka-Fibonacci sequence?
(a) It has a constant difference
(b) It has a constant ratio
(c) Each term depends on previous two terms
(d) It is a decreasing sequence
Answer:
(c) Each term depends on previous two terms

Question 14.
In a Sierpinski Triangle, the number of black triangles increases but the total shaded area with each stage. This happens because
(a) the number follows an AP and the area follows a GP
(b) the number is multiplied by 3 and the area is multiplied by \(\frac{3}{4}\)
(c) both number and area are multiplied by 3
(d) both number and area remain constant
Answer:
(b) the number is multiplied by 3 and the area is multiplied by \(\frac{3}{4}\)

Question 15.
A recursive sequence is defined as t_n = 5, t_n = f_n-1 – 2, n ≥ 2. Find the value of n for which t_n = -5
(a) 4
(b) 5
(c) 6
(d) 7
Answer:
(c) 6

Assertion-Reason

In Q. 1 to 5, two statements are given, one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer from the options (a), (b), (c), and (d) given below.
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
(b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true.

1. Assertion (A): Recursive rules depend on previous terms.
Reason (R): They require earlier values to find the next term.
Answer:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

2. Assertion (A): In a geometric progression, if the common ratio is negative, the sequence alternates between positive and negative terms.
Reason (R): A geometric progression with a negative common ratio will result in terms that have the same sign.
Answer:
(c) Assertion (A) is true, but Reason (R) is false.

3. Assertion (A): The difference between any two consecutive terms in the sequence of numbers √6, √24, √54, √96,… is 3√6.
Reason (R): The sequence of numbers √6, √24, √54, √96,… form an arithmetic progression.
Answer:
(d) Assertion (A) is false, but Reason (R) is true.

4. Assertion (A): The 4th term of the sequence defined by t_n = 2t_n-1 + 3 with t₁ = 1 is 29.
Reason (R): Each term depends on doubling the previous term and adding 3.
Answer:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

5. Assertion (A): If t_n = 5 × \(\left(\frac{1}{2}\right)^{n-1}\), the sequence is decreasing.
Reason (R): The common ratio is less than 1.
Answer:
(a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

Predicting What Comes Next Exploring Sequences and Progressions Class 9 Ganita Manjari Worksheet

Short Answer Type Questions – I

Question 1.
If the 4^th term of an AP is 18 and common difference is 4, find the first term.
Answer:
6

Question 2.
Which term of the AP: 4, 9, 14, … is 89?
Answer:
18^th term

Question 3.
Find the value of x, so that x + 2, 4x – 6 and 3x – 2 are the three consecutive terms of an arithmetic progression.
Answer:
3

Question 4.
Consider the sequence defined by the explicit formula t_n = 3n – 2, where n is a natural number. Write the first 5 terms of the sequence.
Answer:
[1, 4, 7, 10, 13]

Question 5.
Find the n^th term of the geometric progression in which the second term is 12 and the fourth term is 108.
Answer:
4(3)_n-1 or -4(-3)_n-1

Question 6.
Write the recursive formula of a sequence where each term is 3 more than twice the previous term.
Answer:
t_n = 2t_n-1 + 3; n ≥ 2

Question 7.
If the n^th term of a GP is 128 and both the first term a and the common ratio r are 2. Find the value of n.
Answer:
7

Short Answer Type Questions – II

Question 1.
Mihir started working in 2020 at an annual salary of ₹ 600000 and received an increment of ₹ 50000 each year. In which year will his income reach ₹ 1000000?
Answer:
2028

Question 2.
A library assigns codes to books using 2-digit numbers divisible by 5. Find how many such codes exist and find their total sum.
Answer:
18,945

Question 3.
An AP consists of 40 terms in which the 3^rd term is 14 and the last term is 125. Find the 29^th term.
Answer:
92

Question 4.
Find the recursive rule for the following arithmetic progressions.
(a) 12, 7, 2, -3 ….
(b) [/latex]\frac{3}{2}, \frac{7}{2}, \frac{11}{2}, \frac{15}{2}[/latex]
Answer:
(a) t₁ = 12, t_n = t_n-1 – 5, n ≥ 2
(b) t₁ = \(\frac{3}{2}\), t_n = t_n-1 + 2 n ≥ 2

Question 5.
Which term of the progression 18, -12, 8, … is \(\frac{512}{729}\)?
Answer:
9^th term

Question 6.
If the 4^th, 8^th, and 12^th terms of a GP are a, b, and c respectively, then prove that b = √ac.

Question 7.
A computer virus starts by infecting 5 files. In every subsequent hour, the number of infected files doubles, forming the sequence 5, 10, 20, … At which hour will 640 files be infected? Write the explicit and recursive formulas for this growth.
Answer:
8^th hour; Recursive formula: t_n = 5(2)^n-1;
Recursive formula: t₁ = 5, t_n= 2t_n-1, n ≥ 2

Long Answer Type Questions

Question 1.
The sum of the first three terms of a geometric progression is \(\frac{39}{10}\), and their product is 1. Find the common ratio and terms.
Answer:
For common ratio \(\frac{5}{2}\), terms are \(\frac{2}{5}\), 1, \(\frac{5}{2}\)
For common ratio \(\frac{2}{5}\), terms are \(\frac{5}{2}\), 1, \(\frac{2}{5}\)

Question 2.
If 10 times the 10^th term of an AP is equal to 15 times the 15^thterm, show that 25th term of the AP is zero.
Answer:
0

Question 3.
The sum of the 5^th and 9^th terms of an AP is 40, and the sum of the 7^th and 11^th terms is 60. Find the sum of first five terms of the AP.
Answer:
0

Question 4.
Evaluate:
(a) The sum of all integers from 1 to 500 that are multiples of both 3 and 4.
(b) The sum of all integers from 1 to 500 that are multiples of either 3 or 4.
Answer:
(a) 10332
(b) 62751

Question 5.
10 trees are planted in a straight line at equal intervals of 5 metres. To water them, the gardener must bring water for each tree separately from a well 10 metres from the first tree in line with the trees. How much distance will he have to cover in order to water all the trees, if he starts from the well?
Answer:
650 metres

Case-Based Questions

Question 1.
Cable cars at hill stations are one of the major tourist attractions. On a hill station, the length of cable , car ride from base point to topmost point on the hill is 5000 m. Poles are installed at equal intervals on the way to provide support to the cables on which the car moves. The distance of first pole from the base point is 200 m and subsequent poles are installed at equal interval of 150 m. Further, the distance of last pole from the top is 300 m.
Based on above information, answer the following questions using Arithmetic Progression:
(a) Find the distance of the 10^th pole from the base.
Answer:
1550 metres

(b) Find the distance between the 15^th pole and 25^th pole.
Answer:
1500 metres

(c) Find the time taken by cable car to reach the 15^th pole from the top if it is moving at the speed of 5m/sec.
Answer:
9 minutes
OR
Find the total number of poles installed along the entire journey.
Answer:
31 poles

Question 2.
Aryan is studying the Sierpinski triangle, a well-known fractal pattern. The pattern begins with an equilateral triangle (Stage 0), and at each stage, the triangle is divided into 4 smaller triangles. The central triangle is removed, leaving 3 smaller triangles. Aryan has observed the progression of the Sierpinski triangle from Stage 0 to Stage 3 and is now trying to understand the number of black triangles and the area of the black region at each stage.

(a) How many black triangles are there from Stage O to Stage 3 of the Sierpinski triangle?
Answer:
[1, 3, 9, 27]

(b) At which stage will the number of black triangles be 81?
Answer:
Stage 4

(c) Write a rule for the number of black triangles at the n^th stage.
Answer:
3ⁿ
OR
If the area of the black region at Stage 0 is 1 square unit, what is the area of the black region at Stage 5?
Answer:
\(\frac{243}{1024}\) sq.unit

Competency Based Questions

Question 1.
Harsha made a wind chime using a frame and metal rods. She punched 8 holes in the frame, each 2 cm apart, and then hung 6 metal rods from the frame, as shown in the figure. The ends of the metal rods are aligned over a line, shown by the dotted line in the figure. If all of the rods are straight and not swaying, then what is the length of Rod P?

Answer:
\(\frac{111}{7}\) cm

Question 2.
The 3^rd and the 14^th terms of an arithmetic progression are (-9) and (35) respectively. Which term of this arithmetic progression is five times the 6^th term?
Answer:
9^th term

Question 3.
A sequence is defined by the recursive rule: t₁ = 2, t_n = 2 x t_n-1 for n ≥ 2. Find the 10^th term of the sequence.
Answer:
1024

Question 4.
A sequence is defined recursively by the rule t₁ = 5 and t_n = 2t_n-1 + 3 for n ≥ 2. Calculate the 7^th term in the sequence. Also, prove that the general formula for the n^th term of the sequence is tⁿ = 8 × 2_n-1 -3.
Answer:
t₇ = 509

Question 5.
Rakesh was given his pocket money on Jan 1st, 2024. From this money, he puts ₹1 on Day 1, ₹2 on Day 2, ₹3 on Day 3, and continued doing so till the end of the month into his piggy bank. He also spent ₹204 of his pocket money and found that at the end of the month he still had ₹100 with him. How much was his pocket money for the month?
Answer:
₹ 800

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