The box A weighs 20 lb. The rope is wrapped one and one-fourth turns around the fixed wood...

The box A weighs 20 lb. The rope is wrapped one and one-fourth turns around the fixed wooden post. The coefficients of friction between the rope and post are μs = 0.15 and μk = 0.12.

(a) What minimum force does the man need to exert to support the stationary box?

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(b) What force would the man have to exert to raise the box at a constant rate?