What Is the Net Torque on a Uniform Beam?

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To determine the net torque on a uniform beam, calculations are required for both the center of mass (point C) and one end (point P). The total force acting on the beam is 8.5 N, leading to a torque of 38 Nm when multiplied by the beam's length. The correct method for calculating torque involves using the component of the force that is perpendicular to the beam and the distance from the pivot point. For the uppermost force, the torque is calculated as 56*sin(30)*4.5/2. Understanding these principles is crucial for solving problems related to torque on beams.
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Homework Statement



Determine the net torque on the 4.5-m-long uniform beam shown in the figure:
http://session.masteringphysics.com/problemAsset/1057865/3/GIANCOLI.ch10.p030.jpg"

A) Calculate about point C, the center of mass (CM)

B)Calculate about point P at one end.

Homework Equations



\tau=F*\theta

The Attempt at a Solution



In this case I have the answers for the values with the same figure, so I know the summation of forces along this pole must be equal to 8.5 N. From there I multiply the length of my bar to get 38 Nm, which is correct. However, I don't know how to get this from the figure. From there, I have no idea how to get the torque around point p.
 
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The formula is not correct. It should be the component of force perpendicular to the rod times the distance from the point.

For the uppermost force, it would be
Torque = 56*sin(30)*4.5/2
 
Thread 'Correct statement about size of wire to produce larger extension'

Thread 'Correct statement about size of wire to produce larger extension'

The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...
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