The 78 kg climber here is supported in the "chimney" by the friction forces exerted on her shoes and back. the static coefficients of friction between her shoes and the wall, and between her back and the wall, are 0.88 and 0.63, respectively. what is the minimum normal force he must exert? assume the walls are vertical and that friction forces are both at a maximum.
freezing water and exploding dynamite
the angle near the y-axis is 60°, beause 90°-30°=60°. vy=10m/s*sin60°=8.66m/s