A bullet of mass m moving with velocity `upsilon_(1)` strikes a suspended wooden block of mass M as shown in the figure and sticks to it. If the block rises to a height y. the initial of the bullet is

Explanation

Initial kinetic energy of the block when the bullet strikes.
`=(1)/(2)(m+M)v^(2)`
Due to this kinetic energy, the block will block will rise to a height h. Its potential energy =(m+M) gh
So, from the law of conservation of energy
`(1)/(2)(M+m)v^(2)=(M+m) gh implies v=sqrt(2gh)`