The 60 kg climber in Fig. 4-52 is supported in the "chimney" by the friction forces exerted on his shoes and back. The static coefficients of friction between his shoes and the wall, and between his back and the wall, are 0.82 and 0.58, respectively. What is the minimum normal force he must exert? Assume the walls are vertical and that friction forces are both at a maximum.

Answer 1

Draw the free body diagram and use:

mg=N(μ1+μ2)
m=mass of climber
g=acceleration du to gravity
N=minimum normal force, N
μ1 and μ2 = coeff. of friction.