A man wearing a bulletproof vest stands still on roller skates. The total mass is 80 kg. A bullet of mass 20 grams is fired at 400 m/s. It is stopped by the vest and falls to the ground. What is the velocity of the man?
1 Answer
Nov 18, 2015
Explanation:
Using conservation of momentum,
initial momentum = final momentum
m⋅u+M⋅U=m⋅v+M⋅V
0.02⋅400+80⋅0=0.02⋅0+80⋅V
8=80⋅V⇒V=0.1 m/s
Therefore, the man moves with a velocity of
