A plank of length 2l and mass M lies on a frictionless plane. A ball of mass m and speed Vo strikes its end (the plank is standing vertical and the ball strikes the top from the left). Find the final velocity of the ball, Vf, assuming that mechanical energy is conserved and that Vf is along the original line of motion.
b)Find Vf assuming that the stick is pivoted as the lower end.
Ans clue: If m=M, then part a has Vf=3Vo/5 and part b would equal Vf=Vo/2
The solution very clearly explains the problem while calculating the answer.