A projectile is projected with velocity in vertically upward direction from the ground into the space. ( is escape velocity and k<1). If air resistance is considered to be negligible then the maximum height from the centre of earth to which it can go, will be : (R = radius of earth)
(c)Loss in Kinetic energy = Gain in Potential energy
Height of projectile from the earth's surface = h
Height from the centre
By solving