Question

HELP! I GIVE MEDALS!
Two 100 kg bumper cars are moving toward each other in opposite directions. Car A is moving at 8 m/s and Car B at -10 m/s when they collide head-on. If the resulting velocity of Car B after the collision is 8 m/s, what is the velocity of Car A after the collision?

-8 m/s
-10 m/s
0 m/s
10 m/s

Answer 1

ok i think i'm right. but first you need to find the momentum before the collision happens so set that up as \[p_{before}=m_{1}v_{1}+m_{2}v_{2}\] once you find that one then you do the same for the momentum after the collision. it should look like this \[m_{1}v_{1}+m_{2}v_{2}=m_{1,0}v_{1,0}+m_{2,0}v_{2,0}\] and we know some values so plug those in like so \[100v_{1}+(8)(100)=(8)(100)+(10)(100)\] now solve for v

Answer 2

oops. forgot to put a negative in there for the second cart traveling to the left.

Answer 3

\[100v_{1}+(8)(100)=(8)(100)+(-10)(100)\] ok that's should be right now.