Consider a worker using a special wrench to tighten bolts. The couple moment gen
ID: 1606913 • Letter: C
Question
Consider a worker using a special wrench to tighten bolts. The couple moment generated about the long axis of the wrench is M_c = 100 Nm and the distance between the handles of the wrench and the long axis is r = 25 cm. Determine the force exerted by the worker on the handles of the wrench. Consider two divers preparing to dive into a pool in sequence. The horizontal diving board of uniform thickness is mounted to the ground at point O, has a mass of 170 kg, and I = 4 m in length. The first diver has a mass of 86 kg and he stands at point B, which is the free end of the diving board. The second diver has a mass of 82 kg and he stands at point A which is the center of gravity of the board. Furthermore, point A is equidistant from points O and B. Deter mine the moment generated about point O by the weighs of the divers and the board. Calculate the net moment about point O.Explanation / Answer
Net moment M = 2*F*r
F = applied force
r = distance from handle to axis
100 = 2*F*0.25
F = 200 N
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(6)
net moment = (mA*g*l/2) + (mB*g*l) + (Mboard*g*l/2)
net moment = (82*9.8*2) + (86*9.8*4) + (170*9.8*2) = 8310.4 Nm