- #1

tentoes

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## Homework Statement

The problem shows a wrench with a force being applied to one end. Rotation will occur around point P at the opposite end. The force is applied 43 inches to the left from P, and 6 inches above P. The angle theta is between the vertical axis at the end of the wrench (non-p end) and the force being applied - which = 150lb. The problem requires solving for the moment in terms of theta and graphing Mp vs theta. I feel like this should be a super easy problem but I've already given three incorrect answers.

I took the cross product of vector r =<-3.58, 0.5> ft and F = <150cos(theta), 150sin(theta)> and then plugged in values of theta to the result to get that theta = 0, Mp = 537lb/ft, theta = 30, Mp = 502.5, theta = 60, Mp = 333, theta =90, Mp 75. I have no idea what I'm doing wrong here. I also just tried calculating the components of the moment vector and then getting the magnitude for different values of theta by doing sum of the squares...what am I missing?

Just to clarify, the angle theta given in the picture requires that the x component of the force vector use sin(theta), and the ycomponent use cos(theta). Clockwise is supposed to be the positive direction. I feel like this isn't even a question, I have no idea how I could be getting this incorrect.