# Help with forces [closed]

The 72.0 kg climber in the figure 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 0.75 and 0.60, respectively. What is the minimum normal force he must exert? Assume the walls are vertical and that the static friction forces are both at their maximum. Ignore his grip on the rope.

I know Ffr=mu*F(normal force) we also know that F of the shoes against the wall=-F of wall against shoes. Newtons 3rd Law. I just don't know where to start.

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Hi John, and welcome to Physics Stack Exchange! This is a site for conceptual questions about physics, not general homework help. If you can edit your question to ask about the specific physics concept that is giving you trouble, I'll be happy to reopen it. See our FAQ and homework policy for more information. – David Zaslavsky Feb 10 at 21:32

## closed as too localized by John Rennie, David Zaslavsky♦Feb 10 at 21:32

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