A 55 kg rock climber is in a lie-back climb along a fissure, with hands pulling on one side of the fissure and feet pressed against the opposite side. The fissure has width = 0.200 m, and the center of mass of the climber is a horizontal distance d = 0.400 m from the fissure. The coefficient of static friction between hands and rock is µ1 = 0.400, and between boots and rock it is µ2 = 1.20. The climber adjusts the vertical distance h between hands and feet until the (identical) pull by the hands and push by the feet is the least that keeps him from slipping down the fissure. (He is on the verge of sliding.)

a. What is the least horizontal pull by the hands and push by the feet that will keep the climber stable?
b. What is the value of h?