We will have the following:
First, we calculate the momentum before and after, that is:
[tex]\tau_1=(0.01kg)(250m/s)\Rightarrow\tau_1=2.5kg\ast m/s[/tex][tex]\tau_2=(0.01)(120m/s)\Rightarrow\tau_2=1.2kg\ast m/s[/tex]So, the change in momentum is:
[tex]\delta\tau=1.2kg\ast m/s-2.5kg\ast m/s\Rightarrow\delta\tau=-1.3kg\ast m/s[/tex]So, the change in momentum is -1.3kg*m/s.
