A bullet of mass 8.0 g is fired horizontally into a 2.2 kg wooden block at rest on a horizontal surface. The coefficient of kinetic friction between block and surface is 0.40. The bullet comes to rest in the block, which moves 2.30 m. (a) What is the speed of the block immediately after the bullet comes to rest within it?(b) At what speed is the bullet fired?
The energy in the block/bullet combo is forcefriction*distancemoved. Figure that out. Then, set that equal to initial KE of the block/bullet, thence find the initial velocity.
Now use conservation of momentum to find speed of the bullet.