Back to all solutions

SCIENCE CLASS- 9

Class 9 Science Worksheets: Chapter-6

Chapter-wise worksheets with competency-based questions and board exam practice based on the latest CBSE syllabus.

CBSE Latest Syllabus Chapter-wise Worksheets

Chapter 6: How Forces Affect Motion

Class: IX     Subject: Science (Physics)

Name: _______________________     Roll No.: _______________________

Date: _______________________     Marks: 50     Time: 60 Minutes


Section A : Multiple Choice Questions

Choose the correct answer.

  1. Force is
    1. A form of energy
    2. A push or pull
    3. A type of motion
    4. A machine

  2. The SI unit of force is
    1. Joule
    2. Newton
    3. Pascal
    4. Watt

  3. According to Newton's Second Law,
    1. F = mv
    2. F = ma
    3. F = mg
    4. F = m/a

  4. When two equal forces act in opposite directions, the net force is
    1. Maximum
    2. Zero
    3. Double
    4. Negative

  5. Acceleration due to gravity near Earth's surface is approximately
    1. 5 m/s²
    2. 9.8 m/s²
    3. 15 m/s²
    4. 20 m/s²

  6. Momentum depends upon
    1. Mass only
    2. Velocity only
    3. Mass and velocity
    4. Time only

  7. Weight of an object is
    1. m + g
    2. m × g
    3. m ÷ g
    4. g ÷ m

  8. Balanced forces
    1. Always change motion
    2. Always increase speed
    3. Do not change the state of motion
    4. Produce acceleration

  9. Momentum is a
    1. Scalar quantity
    2. Vector quantity
    3. Unit
    4. Force

  10. The SI unit of momentum is
    1. kg·m/s
    2. N
    3. J
    4. kg/m

Section B : Fill in the Blanks and True/False

Fill in the Blanks

  1. The SI unit of force is __________________.
  2. Force = __________________ × Acceleration.
  3. The weight of an object is given by __________________.
  4. Momentum = __________________ × Velocity.
  5. The value of acceleration due to gravity is approximately __________________ m/s².

Write True or False

  1. Force can change the direction of motion. __________
  2. Balanced forces can change the speed of an object. __________
  3. Momentum is a vector quantity. __________
  4. Weight depends on gravity. __________
  5. One Newton is the SI unit of energy. __________

Section C : Match the Following

Column A Column B
1. Newton A. Mass × Velocity
2. Momentum B. F = ma
3. Weight C. SI Unit of Force
4. Newton's Second Law D. mg
5. Balanced Forces E. Net Force = 0

Section D : Short Answer and Numerical Questions

  1. Define force.

  2. Differentiate between balanced and unbalanced forces.

  3. State Newton's Second Law of Motion.

  4. What is momentum?

  5. Define weight. Write its SI unit.

  6. A force of 24 N acts on a body of mass 6 kg. Find its acceleration.

  7. Calculate the weight of a body of mass 8 kg. (Take g = 10 m/s²)

  8. Find the momentum of a body of mass 5 kg moving with a velocity of 4 m/s.

  9. A body starts from rest and accelerates at 3 m/s² for 5 s. Find its final velocity.

  10. A force of 50 N acts on a body and produces an acceleration of 5 m/s². Find the mass of the body.

Section E : HOTS and Case Study

Assertion and Reason

  1. Assertion (A): Balanced forces do not change the state of motion of an object.

    Reason (R): The net force acting on the object is zero.
    1. Both A and R are true and R is the correct explanation.
    2. Both A and R are true but R is not the correct explanation.
    3. A is true but R is false.
    4. A is false but R is true.

  2. Assertion (A): Weight changes from one planet to another.

    Reason (R): Acceleration due to gravity is different on different planets.
    1. Both A and R are true and R is the correct explanation.
    2. Both A and R are true but R is not the correct explanation.
    3. A is true but R is false.
    4. A is false but R is true.

Case Study

A football of mass 0.5 kg is initially at rest. A player kicks the ball, and it starts moving with a velocity of 12 m/s. Later, the goalkeeper stops the ball by applying a force in the opposite direction.

  1. What force changed the state of motion of the football?
  2. Calculate the momentum of the football after it is kicked.
  3. Was the goalkeeper applying a balanced or an unbalanced force while stopping the ball?
  4. What happens to the momentum of the ball when it stops?
  5. Name the law that relates force, mass and acceleration.

Bonus Challenge

A car of mass 1200 kg accelerates uniformly at 2.5 m/s².

  1. Calculate the force acting on the car.
  2. Find the weight of the car. (Take g = 10 m/s²)
  3. Find the momentum of the car if its velocity becomes 20 m/s.
  4. Is momentum a scalar or vector quantity?
  5. State one real-life application of Newton's Second Law.

End of Worksheet