a bullet shot at 500 m/s into a block of wood of mass 0.49kg and becomes in-bedded in it. if it gives the block a speed of 11 m/s, find the mass of the bullet.

This is a conservation of momentum problem.

Mb*Vb = (Mb+Mw)*Vf

The subscripts stand for bulldet, wood and final.

Solve for Mb in this case. You already know Vf.

Vb/Vf = 1 + (Mw/Mb) = 45.45
Mw/Mb = 44.45
Mb/Mw = 0.0225
Mb = ___?