By learning about momentum and impulse, I can now see how it relates to car crashes. If a 1000kg car was going 10m/s, and then a 5000kg truck hit it from behind with a force of 2000N for .5 seconds. You can find the car's change in momentum, or impulse by using the equation J=(m)(change in v). First though, you have to find the final velocity of the cart using F=m(change in v). When plugging in: 2000N=(1000kg)(change in v), velocity equals 2m/s. Then plugging in using the first equation: J=(5000kg)(2m/s), then the impulse would equal 10000kg*m/s.