Halliday, Resnick & Walker — Equilibrium and Elasticity: Problem 11

11 In Fig. 12-22, a climber leans out against a vertical ice wall that has negligible friction. Distance \( a \) is \( 0.914 \text{ m} \) and distance \( L \) is \( 2.10 \text{ m} \). His center of mass is distance \( d = 0.948 \text{ m} \) from the feet–ground contact point. If he is on the verge of sliding, what is the coefficient of static friction between feet and ground?