1. Define force. Is it a vector quantity? What is its unit?

2. State Newton’s first law of motion.

3. Explain why is it dangerous to jump (or alight) from a fast moving bus or train?

4. Why do the dust particles from the hanging blankets fall off by beating with a stick?

5. Which law helps you to find the magnitude of the force acting on a body of mass ‘m’moving with an acceleration ‘a’? State the law.

6. Define momentum. Is it a vector quantity? What is the unit of momentum?

7. How is the rate of change of momentum related to force?

8. Which will have greater momentum—a truck moving with a speed of 60 km/ h or a train moving with the same speed? Justify your answer.

9. Find the acceleration produced in a body of 2 kg mass when a force of 10N acts on it.

10. What force accelerates a 50 kg mass at 6 m/s?

11. A force of 60N accelerates a mass of 15 kg from rest. Find the velocity at the end of 6 seconds.

12. Explain the effect of friction on motion.

13. Give an example to show that friction is useful as well as harmful to us.

14. What is an inverse square law of gravitation?