A 16.0-m uniform ladder weighing 480 N rests against a frictionless wall. The ladder makes a 59.0° angle with the horizontal.
(a) Find the horizontal and vertical forces the ground exerts on the base of the ladder when an 820-N firefighter has climbed 3.90 m along the ladder from the bottom.
Horizontal Force
magnitude
direction
(b) If the ladder is just on the verge of slipping when the firefighter is 9.20 m from the bottom, what is the coefficient of static friction between ladder and ground?