(adsbygoogle = window.adsbygoogle || []).push({}); [SOLVED] change in kinetic energy in a 2-car collision

1. The problem statement, all variables and given/known data

When cars are equipped with flexible bumpers, they will bounce off each other during low-speed collisions, thus causing less damage. In one such accident, a 1850kg car traveling to the right at 1.60m/s collides with a 1450kg car going to the left at 1.10m/s . Measurements show that the heavier car's speed just after the collision was 0.270m/s in its original direction. You can ignore any road friction during the collision.

a) What was the speed of the lighter car just after the collision?

got this to be .597m/s

b) (where I'm stuck) Calculate the change in the combined kinetic energy of the two-car system during this collision.

2. Relevant equations

[tex]\Delta[/tex]K = K2-K1?

3. The attempt at a solution

I'm pretty sure I'm missing something obvious, but I'v tried like 5 different combinations.

(1/2(ma + mb)(v2a+v2b)^2)-(1/2(ma+mb)(v1a+v1b)^2) = 190J wrong

with other combos I've gotten as high as 1490J which was also wrong.

any help is greatly appreciated.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Change in kinetic energy in a 2-car collision

**Physics Forums | Science Articles, Homework Help, Discussion**