Acceleration of two pulleys help

[bcmb146]

Homework Statement

If a₁ and a₂ are the accelerations of m1 and m2, respectively, what is the relation between these accelerations?

Homework Equations

Link to the diagram :
http://www.webassign.net/serpop/p4-38.gif

The Attempt at a Solution

The answer is a₁ = 2*a₂, but I'm having trouble visualizing/understanding how it was gotten. Is there a specific way to do this?

 

[Spinnor]

Get a string or shoe lace and wrap it around a coffee cup. Hold one end of the string still and pull the other end of the string up some distance x, the coffee cup will move x/2.

 

[bcmb146]

I get it now; thanks a lot! I can't believe I didn't even see that in the first place.