How to calculate the Resultant force due to a Lever arm?

  • Thread starter JPakt
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  • #1
JPakt
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Homework Statement:
Need help to find the resultant force at the Point "C" on an object, when a 230-gram force applied at Point "A" which is hinged at point "B".
Relevant Equations:
F1.x1 = F2.x2
1581461413877.png
 

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  • #2
haruspex
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The set up needs more description.
Does the blue line represent a rigid, but bent, arm, or two arms hinged independently at B?
Is B free to move around in space or constrained somehow?
Are there constraints on A's motion?

Also, you need to post an attempt, per forum rules.
 
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  • #3
JPakt
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Thanks for your response.

- 2 Blue Line represents a rigid body
- Point B is hinge support which allows the rotation in an anticlockwise direction and applies force in the direction highlighted at point "C" on a spring.
- Point A represents the CG of the body

Hope I answered your questions.

Please find the attachment which illustrates my attempt to solve the problem.
 

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  • #4
haruspex
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Hope I answered your questions.
Yes, thank you.
The mass is 230gm. That is a mass, not a force, which makes your equations for forces incomplete.
Other than that, your method works, but there is an easier way. You do not need to find F1 to find the torque exerted by the weight. Likewise at the other end.
 
  • #5
JPakt
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Got it. Thanks for your comments.

I appreciate your inputs
 
  • #6
Lnewqban
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You need to determine whether or not those 230 grams are mass or gram-force, in order to provide a proper value for horizontal force at point C.
I recommend creating an orthogonal coordinate system (X-Y axes) with the same orientation of the two forces in the problem.
Disregard the shape and angles of the object, just consider it a disc that pivots around point B.
Then, compute all the forces and moments around the pivot point, considering that the object is in equilibrium.
 

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