# 2 blocks

1. Dec 17, 2014

### Thegiver431

1. The problem statement, all variables and given/known data
A hand pushes on block A. Block B is on the right side of block A. If block a has A mass of 20kg and block B has a mass of 12 kg, and the acceleration equals 4m/s^s, what is the force that block B exerts on Block A

2. Relevant equations
F=m/a

3. The attempt at a solution
F=20kg/4m/s^2 but I am not sure if this, in which I used the mass for block A, is it or if i have to use block B mass. I am kind of confused on which one

2. Dec 17, 2014

### Nathanael

The force that block B exerts on block A is the same as the force that block A exerts on block B (that's one of newton's laws).

You could find this force by evaluating the forces for either block A or block B, but it would be easier to analyze block B.

What are all the forces acting on block B? What is the net force on block B? ($F_{net}=ma$)