# Homework Help: Newton's Laws of Motion (Is my theory correct?)

1. Oct 8, 2014

### math989

1. The problem statement, all variables and given/known data
If two cars of equal mass are pushed apart by a spring mounted on cart #1 with a force of 14 N what will be the resulting acceleration of the carts.

Mass of carts 1 and 2= 2.0Kg
f=14N
A?

2. Relevant equations
F=ma

3. The attempt at a solution
My theory is that the newtons will be distributed between the two carts so that each cart will receive 7N of force. Then i can apply f=ma to solve for the A so 7/2= 3.5m/s^2

2. Oct 8, 2014

### Staff: Mentor

I think you've discovered the center of mass coordinate system for this problem.

Since both carts have the same mass and the spring is pushing the, apart then you
Insight is correct.

Remember that acceleration is a vector so to be absolutely correct you must specify a direction too for each carts acceleration.

3. Oct 9, 2014

### nasu

"Pushed apart with a force of 14 N" means that each cart experiences a force of 14 N.
If they were pushed each by 7 N, there would be no reason to add the 7 by 7 and give a value of 14. The two forces are opposite so their sum is zero and not 14.