Two blocks are connected by a pulley system represented in the diagram below. M1= 60kg and M2=12kg. Wh is the coefficient of friction required to keep the masses at rest?

Hi there!

Assuming the pulley is frictionless and massless, we can do a summation of forces for each block.

Block 1 has the tension force (in direction of acceleration) and force of static friction acting on it. For the block to be stationary, the net force must be 0, so:

Now, we can do a summation for Block 2.

We can substitute this tension in the above equation to solve for the force of static friction and the coefficient of static friction.

not too sure thinking all accelerations are pointed down