Gravitation · Question 56

Two spheres of masses m and M are situated in air and the gravitational force between them is F. The space around the masses is now filled with a liquid of specific gravity 3. The gravitational force will now be

1. 3F
2. F
3. F/3
4. F/9

The acceleration due to gravity on the planet A is 9 times the acceleration due to gravity on planet B. A man jumps to a height of 2 m on the surface of A. What is the height of jump by the same person on the planet B?

1. (2/9) m
2. 18 m
3. 6 m
4. (2/3) m

A body of mass m is placed on earth's surface which is taken from earth surface to a height of h = 3R, then change in gravitational potential energy is

1. mgR4
2. 23mgR
3. 34mgR
4. mgR2

With what velocity should a particle be projected so that its height becomes equal to radius of earth?

1. ( GMR )1/2
2. ( 8GMR )1/2
3. ( 2GMR )1/2
4. ( 4GMR )1/2

For a planet having mass equal to mass of the earth but radius is one fourth of radius of the earth. Then escape velocity for this planet will be

1. 11.2 km/s
2. 22.4 km/s
3. 5.6 km/s
4. 44.8 km/s

A body of weight 72 N moves from the surface of earth at a height half of the radius of earth, then gravitational force exerted on it will be

1. 36 N
2. 32 N
3. 144 N
4. 50 N