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#### Force and Motion Important Questions

7th Standard EM

Reg.No. :
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Science

Time : 01:00:00 Hrs
Total Marks : 50
4 x 1 = 4
1. A particle is moving in a circular path of radius r. The displacement after half a circle would be

(a)

Zero

(b)

R

(c)

2 r

(d)

r / 2

2. Suppose a boy is enjoying a ride on a marry go round which is moving with a constant speed of 10 m/s. It implies that the boy

(a)

at rest

(b)

moving with no acceleration

(c)

in accelerated motion

(d)

moving with uniform velocity

3. What is one way you might increase the stability of an object?

(a)

lower the centre of gravity

(b)

raise the centre of gravity

(c)

increase the height of the object

(d)

shorten the base of the object

4. The slope of a velocity-time graph gives _______

(a)

velocity

(b)

distance

(c)

displacement

(d)

acceleration

5. 4 x 1 = 4
6. The shortest distance between the two places is ______

()

displacement

7. The slope of the speed–time graph gives _____

()

velocity

8. The SI unit of displacement is _____________

()

metre (m)

9. ____________ is the distance trtavelled by a body per unit time

()

speed

10. 5 x 1 = 5
11. Displacement

12. (1)

Metre

13. Speed of ship

14. (2)

Larger base area

15. Stability

16. (3)

Unequal distance covered in equal interval of time

17. Non-uniform motion

18. (4)

Body at rest.

19. Straight line inclined to 45° with time axis is velocity-time graph

20. (5)

Knot

2 x 5 = 10
21. Geetha takes 15 minutes from her house to reach her school on a bicycle. If the bicycle has a speed of 2 m/s, calculate the distance between her house and the school.

22. A bus can accelerate with an acceleration 1 m / s2. Find the minimum time for the bus to reach the speed of 100 km / s from 50 km / s.

23. 3 x 2 = 6
24. velocity : metre/ second : : acceleration : ________

25. length of scale : metre : : speed of aeroplane: ______

26. displacement / time : velocity : : speed / time: ______

27. 6 x 2 = 12
28. All objects having uniform speed need not have uniform velocity. Describe with the help of examples.

29. Correct your friend who says “The acceleration gives the idea of how fast the position changes”.

30. Give one example where the displacement is zero but the distance travelled is not zero

31. Is displacement a scalar quantity?

32. Give one example for uniform acceleration

33. Give one example for non-uniform acceleration

34. 3 x 3 = 9
35. Show the shape of the distance – time graph for the motion in the following cases.
a. A bus moving with a constant speed.
b. A car parked on a road side.

36. What is centre of gravity ?

37. Define speed Mention its formula and unit.