# Thread: Help determining contact force

1. ## Help determining contact force

The problem states that there are two blocks of masses, m1 = 4.00 kg and m2 = 3.00kg, which are placed in contact with each other on a frictionless horizontal surface. A constant force F = 9.00N is applied to the block of mass m1, a) Determine the magnitude of the acceleration of the two-block system, and b) Determine the magnitude of the contact force, P12, between the two blocks.

A is simple a=EF/M = 9N/7KG = 1.29m/s^2 but I cant figure out what formula to use for b although it seems like it should be pretty simple. Any help would be much appreciated.

2. Originally Posted by learningguy
The problem states that there are two blocks of masses, m1 = 4.00 kg and m2 = 3.00kg, which are placed in contact with each other on a frictionless horizontal surface. A constant force F = 9.00N is applied to the block of mass m1, a) Determine the magnitude of the acceleration of the two-block system, and b) Determine the magnitude of the contact force, P12, between the two blocks.

A is simple a=EF/M = 9N/7KG = 1.29m/s^2 but I cant figure out what formula to use for b although it seems like it should be pretty simple. Any help would be much appreciated.
Consider the forces acting on a single blcok that give it its acceleration.