I'm just having trouble setting up this problem. It's based on a picture so I'll describe it:

There is an open ladder standing on the floor with a person on the third step on one side. There is a crossbar attached to the two sides of the ladder and the floor is frictionless. I first need to draw the FOUR forces acting on the ladder.
I'm not sure what the forces are. I think three of them are the weight of the ladder, the weight of the person, and the normal from the floor. Is this correct? What is the fourth force? Something to do with the crossbar?

I assume this is a step ladder.

I think F1 = force up on the left side of the ladder from the floor
F2 = force up on right side of ladder from floor
F3 = weight of man down
F4 = weight of ladder down.

F1 and F2 are separate because they will not be equal and must be calculated separately using moment equilibrium.