posted by bob .
An 77 person stands on a uniform ladder 4.0 long, that weighs 100 , as shown in the figure . The floor is rough; hence, it exerts both a normal force, , and a frictional force, , on the ladder. The wall, on the other hand, is frictionless; it exerts only a normal force, . the forces exerted on the ladder when the person is three-fourths of the way up the ladder.
i don't know this is so tough