Chapter 12, Problem 22P

GO In Fig-12-39, 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 w = 0.20 m, and the center of mass of the climber is a horizontal distance d = 0.40 m from the fissure. The coefficient of static friction between hands and rock is μ₁ = 0.40, and between boots and rock it is μ₂= 1.2. (a) What is the least horizontal pull by the hands and push by the feet that will keep the climber stable? (b) For the horizontal pull of (a), what must be the vertical distance h between hands and feet?If the climber encounters wet rock, so that μ₁ and μ₂ reduced, what happens to (c) the answer to (a) and (d) the answer to (b)?

Figure 12-39 Problem 22.