#### Laws of Motion Book Back Questions

10th Standard

Reg.No. :
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Science

Time : 01:00:00 Hrs
Total Marks : 35
3 x 1 = 3
1. The mass of a body is measured on planet Earth as M kg. When it is taken to a planet of radius half that of the Earth then its value will be____kg

(a)

4 M

(b)

2 M

(c)

M/4

(d)

M

2. If the Earth shrinks to 50% of its real radius its mass remaining the same, the weight of a body on the Earth will

(a)

decrease by 50%

(b)

increase by 50%

(c)

decrease by 25%

(d)

increase by 300%

3. To project the rockets which of the following principle(s) is /(are) required?

(a)

Newton’s third law of motion

(b)

Newton’s law of gravitation

(c)

law of conservation of linear momentum

(d)

both a and c

4. 3 x 1 = 3
5. By convention, the clockwise moments are taken as ___________ and the anticlockwise moments are taken as__________

()

negative and postive

6. ___________ is used to change the speed of car.

()

Gear

7. A man of mass 100 kg has a weight of ___________ at the surface of the Earth

()

980 N

8. 4 x 1 = 4
9. Newton’s I law

10. (1)

propulsion of a rocket

11. Newton’s II law

12. (2)

Flying nature of bird

13. Newton’s III law

14. (3)

Law of force

15. Law of conservation of Linear momentum

16. (4)

stable equilibrium of an object

3 x 2 = 6
17. Why a spanner with a long handle is preferred to tighten screws in heavy vehicles?

18. While catching a cricket ball the fielder lowers his hands backwards. Why?

19. How does an astronaut float in a space shuttle?

20. 3 x 4 = 12
21. A ball of mass 1 kg moving with a speed of 10 ms-1 rebounds after a perfect elastic collision with the floor. Calculate the change in linear momentum of the ball.

22. A mechanic unscrew a nut by applying a force of 140 N with a spanner of length 40 cm. What should be the length of the spanner if a force of 40 N is applied to unscrew the same nut?

23. The ratio of masses of two planets is 2:3 and the ratio of their radii is 4:7 Find the ratio of their accelerations due to gravity.

24. 1 x 7 = 7
25. What are the types of inertia? Give an example for each type.