Solving Acceleration of Blocks in Pulley System

[Thomas_]

Homework Statement

Pulley System:

B-------O	////
//////	|	|
	|	|
	|	|
	 ---O---
	    |
	    B

O = Pulley
B = Block

Find the acceleration of each block in terms of m1,m2 and g.

Homework Equations

F = ma

The Attempt at a Solution

I drew free body diagrams for each block and ended up with:

Block 1: T1 = m1a1

Block 2: m2g - T2 =m2a2
T2 = 2T1

However, this is not enough to cancel out all a2's / a1's. What piece am I missing here?

 

[Doc Al]

However, this is not enough to cancel out all a2's / a1's. What piece am I missing here?

What's the relationship between a_1 and a_2? If m1 has an acceleration of +a to the right, what must the acceleration of m2 be?

 

[ank_gl]

not much is clear from that picture.. mind clarifying it a lil bit??

 

[Thomas_]

What's the relationship between a_1 and a_2? If m1 has an acceleration of +a to the right, what must the acceleration of m2 be?

The same?

not much is clear from that picture.. mind clarifying it a lil bit??

I'm sorry, sure.

http://img299.imageshack.us/img299/3518/clipboard01kg4.th.jpg

 

[Doc Al]

The same?

No. If m_1 moves a distance L to the right, how far down does m_2 move? (You might find it helpful to play around with a piece of string. I'm not kidding.) You need to determine the magnitude and direction of the acceleration of m_2 in terms of the acceleration of m_1.