# Total Momentum

1. Apr 5, 2007

### kitty9035

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

Two identical objects A and B of mass M move on a one-dimensional, horizontal air track. Object B initially moves to the right with speed V0. Object A initially moves to the right with speed 3V0, so that it collides with object B. Friction is negligble. Determine the total momentum of the system of the two objects. Express answers in terms of M and V0.

2. Relevant equations

P=mv

3. The attempt at a solution

I got an answer,but i would like verification that it's right.

I did...

Pa=(Ma)(Va) Pb=(Mb)(Vb)
Pa=m(3V0) Pb=m(V0)

m(3V0) + m(V0)

and get...:surprised

2m + 4v0

2. Apr 5, 2007

### e(ho0n3

That is so wrong and you know it.

3. Apr 5, 2007

### kitty9035

No, I really don't. What's right?

4. Apr 5, 2007

### e(ho0n3

Don't you notice that the expression 2m + 4v0 is non-sense? If not, I suggest you go study some algebra.

5. Apr 5, 2007

### hage567

You're OK up to that last step. 2m + 4v0 does not make any sense. You cannot separate out the variables like that.