Frictionless blocks and a pulley with force F

[zwingtip]

Sort of urgent. I've been looking at this problem for days and it's due tomorrow afternoon.

Homework Statement

Draw a free body diagram for each of the masses. All surfaces are frictionless. The pulley is massless and frictionless. The connecting strings denoted by dotted lines are massless and inextensible. $$M_{1}$$ has no acceleration in the y-direction (forces cancel)

Homework Equations

None

The Attempt at a Solution

I have none. This is part a of a multistep problem and I know how to do the other parts if I can get this part. Unfortunately, I'm awful at free body diagrams, especially in an accelerating system. And it's due tomorrow afternoon. After several days of trying I have nothing to show for it.

EDIT: Have I done this correctly?[PLAIN]http://img828.imageshack.us/img828/1176/img0079hh.jpg
[PLAIN]http://img69.imageshack.us/img69/141/img0080ch.jpg

 

[vela]

Except for m₁a and m₃a, it looks good. Mass 3 exerts a normal force on mass 1 and vice versa. The two forces are an action-reaction pair. For mass 3, the normal force exerted by mass 1 turns out to be equal to m₁a, which is a consequence of F=ma, but the force on mass 1 isn't equal to m₃a.

 

[zwingtip]

Awesome, thanks. I actually already turned in the set, but that's what I changed it to when I realized the forces didn't add up right.