Homework Help: Contact forces?

1. Feb 9, 2008

sailsinthesun

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

Three blocks are in contact with each other on a frictionless, horizontal surface, as in Figure P5.54. A horizontal force F is applied to m1. Take m1 = 2.00 kg, m2 = 3.00 kg, m3 = 4.00 kg, and F = 22.0 N.

(c)What is the magnitude of the contact force between m1 and m2?

(d)What is the magnitude of the contact force between m2 and m3?

http://img129.imageshack.us/img129/3048/p556ow4.gif [Broken]

2. Relevant equations

f=ma

3. The attempt at a solution

I'm clueless, as we haven't be taught anything about contact forces. Any help?

Last edited by a moderator: May 3, 2017
2. Feb 9, 2008

AFG34

First you need to calculate the acceleration of the system because acceleration of all masses are the same. Next you can draw an FBD and use F=ma to solve c) and d)

3. Feb 9, 2008

sailsinthesun

I calculated acceleration of the system to be (22/9)m/s^2.

Would it be F=(m2-m1)a?

4. Feb 10, 2008

AFG34

for C) draw an FBD for M2