Gravitation Tes...

A body of mass $$m$$ is raised to a height $$h$$ above the surface of the earth of mass $$M$$ and radius $$R$$ until its gravitational potential energy increases by $$\dfrac{1}{3} mgR$$. The value of $$h$$ is 

The value of acceleration due to gravity on Mount Everest is

Choose the correct statement:

The height at which the value of acceleration due to gravity becomes $$50$$% of that at the surface of the earth. ( Radius of the earth=6400 km) is 

A man weighs $$'W'$$ on the surface of the earth and his weight at a height $$'R'$$ from surface of the earth is ( R is Radius of the earth)

If retardation produced by air resistance of air resistance is one - tenth of acceleration due to gravity. the time to reach maximum height.

An express train is moving with a velocity $$\mathbf { V } _ { 1 }$$ Its driver finds another train is moving on the same track in the same direction with velocity $$v _ { 2 }$$ s. To escape collision. driver applies retardation a on the train. The minimum time of escaping collision will be 

Ratio of gravitational force acting on body at height $$1600\ km$$ to gravitational force acting on the same body on Earth's surface $$(R = 6400\ km)$$.

Kepler's law of area is based on

The gravitational potential energy of an object is due to