A 35 g bullet strikes a 5 kg stationary block and embeds itself in the block. The block and bullet fly off together at 8.6 m/s What was the original speed of the bullet?

Hi there!

We can use the conservation of momentum for a perfectly inelastic collision to solve.

m1, v1 = mass and velocity of bullet (0.035 kg and ? m/s respectively)

m2, v2 = mass and velocity of block (5 kg and 0 m/s respectively)

vf = combined final velocity (8.6 m/s)

Plug in the givens and solve:

answer( sicar );

it is b. absorbs thermal energy