Bullet hits block and gets lodged into the block. After this, block + bullet system moves to rise upto height h Let, v = common velocity of block and bullet with which mass system begins to rise. This is an example of perfectly inelastic collision, hence according to conservation of linear momentum, ⇒‌‌mv0=(m+M)v So, ‌‌v=‌
mv0
(m+M)
∴ Loss of KE = Final KE of system - Initial KE of bullet =‌