A wooden ball of density D is immersed in water of density d to a depth h and then released . The height  above the surface of water up to which the ball will jump out of water is ( neglect viscous effect )

Let the volume of the ball be V. Force on the ball due to upthrust =V d g Net upward force =V d g -V D g .'. Upward accelemtion is given bY VDa=Vdg−VDg a=d−DDg  velocity on reaching the surface, u=2ah  Further u=2gH ∴ 2ah=2gH  or  H=ahg  So,  H=d−DDh=dD−1h