# Answer to Question #3708 in Mechanics | Relativity for marisa

Question #3708

2200 kg car moving at 40 km/h collides head on with an 1800 kg car moving at 20 km/h. find the velocity of the combined cars after the collision.

Expert's answer

m1Vi1+m2Vi2=(m1+m2)Vf

2200(40)+1800(-20)=(2200+1800)Vf

88000-36000=4000Vf

52000/4000=Vf

Vf=13km/hr

## Comments

Assignment Expert05.12.18, 22:55Dear Megan, you're right. Thank you for your comment.

Megan04.12.18, 17:30actually though your close its just not quite the right answer. Since its a head on collision one of cars would need to have a negative moment. so

m1Vi1+m2Vi2=(m1+m2)Vf

2200(40)+1800(-20)=2200+1800Vf

88000-36000=4000Vf

52000/4000=Vf

Vf=13km/hr

## Leave a comment