Question

A 10 gram bullet hits and becomes embedded in a 2 kg block of wood which is initially at rest.
What was the bullet's speed before the collision if the combination has a speed of 3 m/s after
the collision?

Linear momentum : my question is - Is this an isolated system or non-isolated? Please tell me which one .

Answer 1

need to do it with forces or energy?

Answer 2

Energy

Answer 3

So use conservation of linear momentum
p = mv
so
\[m_{1}v + m_{2}v = (m_{1}+m_{2})V_{f}\]
Now plug in .The wood is at rest so v wood = 0
\[m_{1}v + m_{2}(0) = (m_{1}+m_{2})3\]
10(v) = 12(3)
36/10 = v initial of bullet

Answer 4

Thank you !