What was the speed of the bullet?

Question

A 10 g bullet is fired into a 10 kg wood block that is at rest on a wood table. The block, with the bullet embedded, slides 5.0 cm across the table. The coefficient of kinetic friction for wood sliding on wood is 0.20.

Answer 1

Step 1, compute the speed of the block and bullet
using energy
.5*10.01*v^2=10.01*9.81*0.20*0.05
solve for v
v=0.44 m/s

now, compute bullet speed using conservation of momentum

0.01*v=10.01*0.44
solve for v
440 m/s

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