Two balls A and B are thrown vertically upwards from the same location on surface of earth with velocities 2(gR/3)^1/2 and (2gR/3)^1/2 respectively, where g is acceleration due to gravity on the earth's surface and R is the radius of the Earth. Determine the ratio of maximum height attained by A to that attained by B.
I just know answer is 4:1.