- #1
tdashrom
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Homework Statement
I'm supposed to be finding the net torque on a square plate. The sides are 1.7 m in length, with a force acting on each corner (30 N top left pointed right, 60 N top right pointed down, 20 N bottom left pointed up, and 40 N bottom right at an angle of 37 degrees). Just for simplicity I have included the picture of the question, and WebAssign has given the answer.
Homework Equations
τ=Frsin(Θ)
The Attempt at a Solution
I understand how to get part b from the solution in part a. However, I'm completely stuck on how the answer in part a is reached.
The radius in this case should be 1/2 of the side length, so 0.85 m. The 20, 30, and 60 N forces should all have negative torque values because they are turning clockwise, and the 40 N force will be positive. I have tried -.85*(20+30+60)+(40*sin(37)*.85), which does not give the correct answer. If you multiply the three CW forces by sin(45) you get -45.6, which while close is not accepted by the system. I've reworked this 10 times multiple different ways, but still to no avail. Where am I going wrong?