# Motion Under Gravity – Old Year Questions

1. Who among the following anticipated Newton by declaring that all things gravitate to the earth?

(a) Aryabhatta
(b) Varahamihira
(c) Buddhagupta
(d) Brahmagupta

[I.A.S. (Pre) 1995]

2. Who gave the theory of gravity?

(a) Charles Newton
(b) Charles Babbage
(c) Isaac Newton

[M.P.P.C.S. (Pre) 2010]

3. Who propounded the universal law of gravitation?

(a) Newton
(b) Galileo
(c) Copernicus
(d) Einstein

[M.P.P.C.S. (Pre) 2000, Uttarakhand U.D.A./L.D.A. (Pre) 2007]

4. Astronauts in space can not stand erect. This is because in space –

(a) There is no gravity
(b) Viscous forces of the atmosphere are very strong
(c) Solar wind exerts an upward force
(d) Atmospheric pressure is very low

[U.P.P.C.S. (Mains) 2007]

5. If an apple is released from an orbiting spaceship, it will –

(a) Fall towards the Earth
(b) Move at a lower speed
(c) Move along with the spaceship at the same speed
(d) Move at a higher speed

[U.P.P.C.S. (Pre) 2010]

6. The Leaning Tower of Pisa does not fall because –

(a) It is tapered at the top
(b) It covers a large base area
(c) Its centre of gravity remains at the lowest position
(d) The vertical line through the centre of gravity of the tower falls within its base

[U.P.P.C.S. (Pre) 2009]

7. If the distance between the Earth and the Sun were twice what it is now, the gravitational force exerted on the Earth by the Sun would be –

(a) Twice as large as it is now
(b) Four times as large as it is now
(c) One-fourth of what it is now
(d) Half of what it is now

[U.P.P.C.S. (Mains) 2009]

8. If an object is falling from above, its weight remains –

(a) Zero
(b) Same
(c) Change
(d) None of the above

[M.P. P.C.S. (Pre) 1992]

9. If pieces of equal size of wood, wax, and iron fall from the same height, which one will reach the surface of the earth first?

(a) Wood
(b) Wax
(c) Iron
(d) Reach at the same time

[R.A.S./R.T.S. (Pre) 1992]

10. The two balls of iron and wood of the same weight dropped from the same height in air, then –

(a) They reach the ground (earth) at the same time.
(b) One falls first, another falls later.
(c) The wooden ball falls later.
(d) They reach the ground after some gap.

[U.P.P.C.S. (Pre) 1992]

11. Two balls A and B are of 10 kg. and 1 kg. respectively. They are dropped simultaneously from a height of 20m. Which of the following is correct?

(a) A will reach the ground first
(b) B will reach the ground first
(c) Both A and B will reach the ground at the same time
(d) None of the above

[U.P. Lower Sub. (Pre) 2015]

12. Assertion (A) :The weight of human being on the moon is 1/6 in comparison to earth.
Reason (R) :The moon does not have gravity like earth.

Select the answer from following codes –

(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

[Chhattisgarh P.C.S. (Pre) 2008]

13. The weight of anybody is –

(a) Same at every place on earth’s surface
(b) Maximum at poles
(c) More on equator
(d) More on mountains than in planes

[U.P.P.C.S. (Mains) 2009, U.P.P.C.S. (Pre) 2006]

14. The weight of human body is –

(a) Maximum at the poles.
(b) Same at every place on the earth’s surface.
(c) Maximum at the equator.
(d) More on the mountains than planes.

[U.P.P.C.S. (Mains) 2015]

15. A ball is dropped from the top of a high building with a constant acceleration of 9.8 m/s². What will be its velocity after 3 seconds?

(a) 9.8 m/s
(b) 19.6 m/s
(c) 29.4 m/s
(d) 39.2 m/s

[I.A.S. (Pre) 1998]

16. If the radius of the earth were to shrink by one percent, its mass remaining the same, the value of g on the earth’s surface would :

(a) Increase by 0.5%
(b) Increase by 2%
(c) Decrease by 0.5%
(d) Decrease by 2%

[I.A.S. (Pre) 2003]

17. The acceleration due to the gravity of a destructive earthquake will be –

(a) > 550 cm/sec²
(b) > 750 cm/sec²
(c) > 950 cm/sec²
(d) > 980 cm/sec²

[I.A.S. (Pre) 1994]

18. The mass of a body on the Earth is 100 kg (acceleration due to gravity, ge= 10m/s2 ). If acceleration due to gravity on the Moon is ( ge/6), then the mass of the body on the Moon is :

(a) 100/6 kg
(b) 60 kg
(c) 100 kg
(d) 600 kg

[I.A.S. (Pre) 2001]

19. Weightlessness is –

(a) Zero gravity
(b) When gravity decrease
(c) In a vacuum
(d) None of the above

[M.P.P.C.S. (Pre) 1991]

20. The Earth travels in its orbit at a speed of approx 4,400 km per hour. Why do we not feel this high speed?

(a) Because we are too small compared to the size of the earth.
(b) Our relative speed with respect to the Earth along the earth’s orbit is zero.
(c) The solar system as a whole is also moving.
(d) The gravity of the Earth constantly pulls us towards the Earth’s centre.

[U.P.P.C.S. (Mains) 2013]

21. If the gravitational force of the earth suddenly disappears, which of the following will be the correct consequence?

(a) The weight of an object will become zero but the mass will remain the same.
(b) The mass of the object will become zero but the weight will remain the same.
(c) Both the mass and the weight of the object will become zero.
(d) The mass of the object will increase.

[U.P.P.C.S. (Mains) 2012]

22. An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth –

(a) Does not exist at such distance
(b) Is neutralized by the attraction of the Moon
(c) Provides the necessary speed for its steady motion
(d) Provides the necessary acceleration for its motion

[I.A.S. (Pre) 2011]

23. Satellite is kept moving in its orbit around the Earth; it is due to –

(a) Centrifugal force
(b) Centripetal force
(c) Gravitational force or lack of it
(d) Some other forces

[U.P.P.C.S. (Mains) 2013]

24. A Geosynchronous satellite continuously active in its orbit due to centripetal force which is obtained by

(a) The rocket engine that propelled the satellite.
(b) The gravitational force on the satellite by the earth.
(c) The gravitational force on the satellite by the sun.
(d) The gravitational force on the earth by satellite.

[U.P.P.C.S. (Pre) 2006]

25. The known forces of nature can be divided into four classes, viz, gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them which one of the following statements is not correct?

(a) Gravity is the strongest of the four
(b) Electromagnetism acts only on particles with an electric charge
(c) Weak nuclear force causes radioactivity
(d) Strong nuclear force holds protons and neutrons inside the nucleus of an atom

[I.A.S. (Pre) 2013]

26. If a person sitting in a lift then when will he feel that his weight gets increased?

(a) When the elevator going upward expeditiously
(b) When the elevator going down expeditiously.
(c) Going upward with constant velocity.
(d) Going downward with constant velocity.

[U.P.P.C.S. (Pre) 1990]

27. The time period of a pendulum –

(a) Depends on the mass
(b) Depends on its length
(c) Depends on time
(d) Depends on temperature

[47th B.P.S.C. (Pre) 2005]

28. Why do pendulum clocks usually lose time in summer?

(a) Due to longer days in summer.
(b) Due to friction caused by coils.
(c) The length of the pendulum increases, increasing the time period of unit oscillation.
(d) The weight of the pendulum change in summer.

[U.P.P.C.S. (Pre) 2012, U.P.P.C.S. (Pre) 1994]

29. A girl is swinging on a swing in sitting position. When the girl stands up, the period of the swing will :

(a) Be shorter
(b) Be longer
(c) Depends on the height of the girl
(d) Not change

[I.A.S. (Pre) 1997]

30. Consider the following statements :

A Simple Pendulum is set into oscillation Then :
1. the acceleration is zero when the bob passes through the mean position.
2. in each cycle the bob attains a given velocity twice.
3. both acceleration and velocity of the bob are zero when it reaches its extreme position during the oscillation.
4. the amplitude of oscillation of the simple pendulum decreases with time.

Which of these statements are correct?

(a) 1 and 2
(b) 3 and 4
(c) 1, 2 and 4
(d) 2, 3 and 4

[I.A.S. (Pre) 2001]

31. A pendulum clock can run faster in –

(a) Summer
(b) Winter
(c) Spring season
(d) Rainy season

[R.A.S./R.T.S. (Pre) 1997]

32. Earth’s escape velocity is –

(a) 15.0 km/sec.
(b) 21.1 km/sec.
(c) 7.0 km/sec.
(d) 11.2 km/sec.

[R.A.S./R.T.S. (Pre) 1993]

33. What will happen if an object is thrown into space with the speed of 8 km/sec.?

(a) The object will go into space
(c) It will rotate into the orbit of earth
(d) It will burst out

[R.A.S./R.T.S. (Pre) 1992]

34. There is no atmosphere on the moon because –

(a) It is near to the earth.
(b) It receives light from the sun.
(c) It revolves around the earth.
(d) The escape velocity of gas molecules on it is less than the root mean square velocity here.

[U.P.P.C.S. (Mains) 2012]

35. Given below are two statements

Assertion (A): Lighting a candle in space does not produce fame.
Reason (R) : A fame exists due to the pull of gravity.

In the context of above, which one of the following is correct?

(a) Both (A) and (R) are true and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true but (R) is not the correct explanation.
(c) (A) is true but (R) is false.
(d) (A) is false but (R) is true.

[U.P.P.C.S. (Pre) 2009]

36. In the state of weightlessness, the size of candle’s fame will be-

(a) Longer
(b) Smaller
(c) Spherical
(d) Constant

[R.A.S./R.T.S. (Pre) 2005]