Please somebody help me with this problem

[angina1]

I am looking for help to solve this problem A 100kg mover is trying to push a 220kg refrigerator with a force F=500N at 0 degrees. Draw or describe free-body diagram showing all the forces acting on the refrigerator and calculate the minimum static coefficient of friction us between the refrigerator and the floor that is necessary for the refrigerator to resist any movement.

I know that the forces acting in the vertical direction is a normal force and the weight of the refrigerator but I am confused about the forces acting in the horizontal direction

 

[berkeman]

The mover is exerting the horizontal force on the refrigerator. They don't tell you what kind of shoes the mover has (what their coefficient of friction is), so assume that the mover is somehow braced against something. Besides, at only 100kg compared to the 220kg refigerator, the mover had better have something to brace against, or else they need to put something slippery (or dowels) under the 'fridge.

What is the equation for the maximum horizontal static friction force that the 220kg object can generate, given its mass and coefficient of static friction?