physics help please?

Question

A projectile (mass = 0.214 kg) is fired at and embeds itself in a target (mass = 2.43 kg). (The target is initially stationary). The target (with the projectile in it) flies off after being struck. What percentage of the projectile's incident kinetic energy does the target (with the projectile in it) carry off after being struck?

Answer 1

You can use the momentum equation for totally inelastic collisions:
mp*u1 + mt*u2 = (mp + mt)*v
where mp = mass projectile, u1 = initial velocity projectile, mt = mass target, u2 = initial velocity target, v = final velocity both.

Then use the kinetic energy equation on the before and after conditions and find the %.