Question

A boy can jump to a height h on ground level. What should be the radius of a sphere of density d such that on jumping on it, he escapes out of the gravitational field of the sphere

Answer 1

Correct option (c)

Explanation

When a boy jumps from a ground level up to height h then its velocity of jumping v = √2gh …..(i)

and for the given condition this will become equal to escape velocity vescape 

…..(ii) 

Equating (i) and (ii)