If the acceleration due to gravity on the surface of earth is g, then the acceleration due to gravity on the surface of a planet whose mass is same as that of earth and radius is half as that of earth is _________________.
Due to an acceleration of 4 m/s2 the velocity of a body increases from 10 m/s to 30 m/s in a certain period. Find the displacement (in m) of the body in that period.