A thin spherical shell of mass 4.00kg and diameter of 0.200m is filled with Helium(density p= 0.180 kg/ms). It is then released from rest on the bottom of a pool of water that is 4.00m deep.
(a) Neglecting frictional effects, show that the shell rises with constant acceleration and determine the value of that acceleration.
(b) How long will it take for the top of the shell to reach the water surface?