A bullet of mass 50g is fired with a velocity of 200m/s in to a block of mass 950g at rest. Given the block can more firely, calculate: 1) the kinetic energy after impact 2) the lose of energy

Conservation of Momentum

mv=(M+m)V'
solve for V' KE after impact = 1/2 (m+M)V'^2
energy lost:1/2 mv^2-1/2 (M+m)V'^2