Simple beginning physics, mindfart

[Jake4]

Homework Statement

2 blocks are suspended on the sides of a table, over pulleys, connected to a central block on the table. From the left to the right, the masses are 4kg, 2kg and 6kg. There is a friction coefficient of 0.12 on the middle block. Find the acceleration.

Homework Equations

F=ma, of course

The Attempt at a Solution

For some reason, I'm having trouble with the center block. I have drawn free-body diagrams for each object, and at the center, I'm having trouble with determining the x-axis forces.

I have marked friction in the opposite direction of the acceleration, but can't seem to figure out how to factor in Tension, as there should be tension on both sides of the object.

This, I know is a very simple thing, but for some strange reason, I'm hung up on it.

 

[ehild]

Show your equations. Do not forget that there are different tensions in the ropes at the opposite sides of the middle block.

ehild

 

[ashishsinghal]

In a single massless string, tension is same. Use it to get forces in x axis