A 14.0-m uniform ladder weighing 510 N rests against a frictionless wall. The ladder makes a 63deg angle with the horizontal.
a) Find the horizontal and vertical forces the ground exerts on the base of theladder when an 850-N firefighter has climbed 3.70 m along the ladder from the bottom.
b) If the ladder is just on the verge of slipping when the firefighter is 9.10 m from the bottom, what is the coeffecient of static friction between ladder and ground?