# Homework Help: Blocks on a slant(with friction)

1. Oct 23, 2007

### rphmy

This is the problem:

Three blocks on a frictionless incline are in contact with each other as shown in the following figure. A force F is applied to block 1 (mass m1), so the whole system moves up the incline.
a) Draw a free body diagram for each block.
b) Determine the acceleration of the system.
c) Determine the net force on each block.
d) What is the force of contact that each block exerts on its neighbor?

I can draw the free body diagram

I tried to determine the acceleration by saying

a=[(g*sin(angle))-(mu*g*cos(angle))]/[(m1+m2+m3)]

I think Fnet= Fp-Ffr

I also think the Fcontact=Fp*number of sides in contact with another block

Please any help would be much appreciated3

2. Oct 23, 2007

### Staff: Mentor

Use that to apply Newton's 2nd law to each block.

Where does this come from? Note that this equation has friction and leaves out the force F. It doesn't even have the right dimensions.

Apply Newton's 2nd law to each block separately. You can also apply it to all three blocks considered as a single system.