Chapter 9 | Force And Laws Of Motion |Test Assignment| Support Material | Assignment Questions | Class 9th Science

Chapter 9 | Force And Laws Of Motion | Support Material | Assignment Questions | Class 9th Science 

VERY SHORT ANSWER TYPE QUESTIONS (1 Mark)

1. Can force be (−)ve ? When ?

2. What is the tendency of a body to resist its change of state called ?

3. Inertia is also measured by.................of an object.

4. Higher the mass of an object, higher is its................. .

5.Force Acceleration is determined by.................which is also mass of the object.

6. Why does the load from the cage above the seats in a bus falls down when suddenly brakes are applied ?

SHORT ANSWER TYPE QUESTIONS (2 Marks)

1. Quantity of motion contained in a body is................. .

2. Unit of momentum is................. .

3. Define 1 Newton.

4. Although we know that a moving body keeps moving indefinitely until an external force is applied on it, then why does a ball stops when we slide it on ground (without stopping it) ?

5. Why is it difficult to stop a truck suddenly than a motorbike ?

6. Why do we jerk forward when a moving bus suddenly stops ?

7. Why do we jerk backwards when a bus suddenly starts moving ?

8. I noticed that when my car takes a right or left turn on a road my body moves in opposite direction. Can you find out why?

SHORT ANSWER TYPE QUESTIONS (3 Marks)

1. When a metro suddenly stops all the passengers fell forward on its floor. Why do this happen ?

2. We have a huge atmosphere above us that exerts a huge pressure on our shoulders, head and whole body. Why don’t we get crushed under it ?

3. A coin of mass 1 kg and a stone of mass 5 kg are thrown down the Eiffel Tower with  an acceleration of 10 m/s 2 . Which one would reach the ground early and why ?

4. Give applications of Ist law of motion i.e., inertia.

 5. (a) Friction is measured in.................. .

     (b) Distinguish between balanced and unbalance forces.

LONG ANSWER TYPE QUESTIONS (5 Marks)

1. Cite 5 examples of Newton’s third law of motion from our surroundings.

2. Prove the law of conservation of momentum.

3. (a) Derive first law of Newton from second law.

    (b) Find the force required to stop a car of mass 100 kg with two passengers each of  50 kg sitting  inside, if it is moving at 60 km/hr speed and takes 5 s to stop.

4. Two balls A and B of masses 40 g and 50 g are moving at speeds of 40 m/s and 30 m/s respectively. If after colliding, B stars moving with a velocity of 25 m/s, what is the velocity of A ?

5. A girl of mass 30 kg jumps on a cart of mass 5 kg with a velocity of 10 m/s. Find          the velocity with which she and cart start moving after she jumps on it.