Calculating Contact Forces between Blocks

[sailsinthesun]

Homework Statement

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

Homework Equations

f=ma

The Attempt at a Solution

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

 

[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)

 

[sailsinthesun]

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)

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

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

 

[AFG34]

for C) draw an FBD for M2