Question
A body is projected vertically upwards. There are two instants when the body will be at same height. Show that the ratio of the two instants when the body will be at height three fourth of its greatest height is 3.
Solution
Let a body be projected with velocity u in vertically upward direction from ground and attain the maximum height H.
Let at any instant t, it is at a height h.
Thus,
Let at any instant t, it is at a height h.
Thus,
