# Find the velocity of two carts after a head on elastic collision.

1. Dec 1, 2012

### Interception

1. The problem statement, all variables and given/known data Two carts of equal mass (15 Kg) have a head on elastic collision. The first cart has a velocity of 18.5 m/s to the right, and the second has a velocity of 12 m/s to the left. What are the velocities of the two carts after the collision?

2. Relevant equations Since it is considered a fully elastic collision, we can assume the conservation of momentum and conservation of kinetic energy apply. So we have m(A)v(A) + m(B)v(B) = m(A)v*(A) + m(B)v*(B) and
1/2m(A)v^2(A) + 1/2m(B)v^2(B)=1/2m(A)v*^2(A) + 1/2m(B)v*^2(B)
Sorry for the sloppy input. I don't really know how to use the symbols right. It just looks like a lot of computer slang mumbo jumbo.

3. The attempt at a solution- In class we went over using both equations to solve for each of the unknown variables. However, we only did one practice problem a week or two after we covered the unit so it didn't really stick. I'm good at math, so once I understand the process it's cake. I'm just trying to figure it out and could use some help on what method to take. If someone could help direct me I'd really appreciate it.

2. Dec 1, 2012

### jhosamelly

Yu have the equation. Just substitute the given values. But remember. Velocity should be - when directed to the left. :)

3. Dec 3, 2012

### WillemBouwer

Interception: List your known parameters, fit it into your 2 equations. How many variables do you have left and how many equations?