A block of wood with a mass M=4.65 kg is resting on a horizontal surface when a bullet with a mass m=18g and moving with a speed v= 725m/sec. strikes it. The cofficient of friction between the block and the surface is =0.35. The distance the blokc moves across the surface is?

The bullet has kinetic energy . The coefficient of friction between the block and the surface consumes all of that kinetic energy. ( where μ is the coefficient of friction and N is the "normal" (downward) force). You simply have to figure out the distance to consume that much energy.

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