Two men exert forces F 80 lb and P 50 lb on the ropes Dete

Two men exert forces F = 80 lb. and P = 50 lb. on the ropes. Determine the moment of each force about A. Which way will the pole rotate, clockwise or counterclockwise?

Solution

angle made by F with pole is @ then

moment due to F = 12 x F x sin@ = 12 x 80 x 4/5 = 768 lb-ft cw

moment due to P = (12 + 6) x P x sin45 = 636.5 lb-ft ccw

net moment = 768 - 636.5 = 131.6 lb-ft clockwise.

as net moment is not zero so they will be able to rotate the pole.

direction = clockwise