A 14.0 m uniform ladder weighing 490 N rests against a frictionless wall. The ladder makes a 61.0-angle with the horizontal. (a) Find the horizontal and vertical forces (in N) the ground exerts on the base of the ladder when an 840-N firefighter has climbed 3.70 m along the ladder from the bottom. horizontal force magnitude N direction --Select--- vertical force magnitude N direction ---Select--- v (b) If the ladder is just on the verge of slipping when the firefighter is 9.30 m from the bottom, what is the coefficient of static friction between ladder and ground? (c) What If? If oil is spilled on the ground, causing the coefficient of static friction to drop to half the value found in part (b), what is the maximum distance (in m) the firefighter can climb along the ladder from the bottom before the ladder slips? m