Finding friction coefficient when pulley system is at equilibrium

[minadd]

Homework Statement

It is given that that block a (.5kg) is on a flat surface at rest and block b (.2kg) is hanging over a table attached to a pulley. I tried to find friction but im stuck. And I still have to find tension for block a and b. I've had experience will inclines but forgot how to do flat surfaces...

Relevant Equations

Fg = mg
g= 9.81ms^2
(Sigma)F = ma
Ff = (mu)Fn

Given:
(block a) m = .500kg
(block b) m = .200kg
that's all...
Fg (block a) = (.5)(9.81) = 4.905N = Fn
Fg (block b) = (.2)(9.81) = 1.962N

i think acceleration might go like...
a = (1.962)/(.5 + .2) = 2.8m/s^2 but isn't it supposed to be at equilibrium? So 0m/s^2.
How am I supposed to find friction without acceleration?

the photo attached is the question.

 

[tnich]

Homework Statement: It is given that that block a (.5kg) is on a flat surface at rest and block b (.2kg) is hanging over a table attached to a pulley. I tried to find friction but I am stuck. And I still have to find tension for block a and b. I've had experience will inclines but forgot how to do flat surfaces...
Homework Equations: Fg = mg
g= 9.81ms^2
(Sigma)F = ma
Ff = (mu)Fn

Given:
(block a) m = .500kg
(block b) m = .200kg
thats all...
Fg (block a) = (.5)(9.81) = 4.905N = Fn
Fg (block b) = (.2)(9.81) = 1.962N

i think acceleration might go like...
a = (1.962)/(.5 + .2) = 2.8m/s^2 but isn't it supposed to be at equilibrium? So 0m/s^2.
How am I supposed to find friction without acceleration?

the photo attached is the question.

You are trying to jump to the end without doing the work of setting up the problem. The first task to draw the FBDs, the same as every other mechanics problem. Once you have all of the forces on each mass drawn and labeled, you can write the force balance equation for each mass and solve the equations.
One thing that might help: static friction is a force that holds an object still by preventing it from sliding along a surface. It is directly proportional to the normal force of the surface on the object.

 

[haruspex]

static friction is a force that holds an object still by preventing it from sliding along a surface. It is directly proportional to the normal force of the surface on the object.

Small correction: the maximum static friction force is directly proportional to the normal force of the surface on the object. The actual force is whatever force, up to that limit, that is required to prevent sliding.