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## Homework Statement

Consider a bullet of mass m fired at a speed of V

_{0}into a wooden block of mass M. The bullet instantaneously comes to rest in the block. The block with the embedded bullet slides along a horizontal surface with a coefficient of kinetic energy [tex]\mu[/tex].

How far does the block slide before it comes to rest? Express your answer in terms of m, M, [tex]\mu[/tex] and g.

## Homework Equations

W = Fs

W = KE

_{f}- KE

_{0}

where s = displacement

## The Attempt at a Solution

I started by saying W = Fs and thought the only net force working here is kinetic friction.

so W = F

_{N}[tex]\mu[/tex] s and since F

_{N}= mg i said...

W = (m +M)g [tex]\mu[/tex]s

then i said since W = KE

_{f}- KE

_{0}....

(m + M)g[tex]\mu[/tex]s = KE

_{f}- KE

_{0}

is this the right appoach?

I cant use conservation of momentum since the sum of external forces arent 0, im assuming since they give the coefficient of kinetic friction.