Question

HOMEWORK QUESTION: *A 0.01 kg bullet is fired at 250 m/s into a wooden block that is fixed. The bullet emerges from the block with a speed of 120 m/s. What is the change in momentum of the bullet?

Answer 1

We will have the following:

First, we calculate the momentum before and after, that is:

`\tau_1=(0.01kg)(250m/s)\Rightarrow\tau_1=2.5kg\ast m/s`
`\tau_2=(0.01)(120m/s)\Rightarrow\tau_2=1.2kg\ast m/s`

So, the change in momentum is:

`\delta\tau=1.2kg\ast m/s-2.5kg\ast m/s\Rightarrow\delta\tau=-1.3kg\ast m/s`

So, the change in momentum is -1.3kg*m/s.