How Much Force to Lift a Pivoting Beam at an Angle?

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To lift a 42" long, 50 lb beam pivoting at one end, the force applied at a 45-degree angle, 12 inches from the pivot, must exceed the moment created by the beam's weight acting at its midpoint (21"). The moment is calculated using the formula: moment = normal force * moment arm. As the beam rotates, the normal component of the weight changes, affecting the required lifting force. Understanding the relationship between the applied force and the moments is crucial for solving this engineering problem. This discussion highlights the importance of analyzing forces and moments in mechanical systems.
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I have another question maybe someone can help me with. I have attached a drawing of a beam (tube) that is 42" long and weighs 50 lbs. The beam pivots at one end (red dot). If the beam weighs 50 lbs how much force is required to lift the beam to a vertical position if I apply force at a 45 degree angle, 12 inches from the pivot point? If anyone has a formula I would appreciate it as I would like to play around with the angle and distance of applied force. Thanks again!
 

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This is simply a moment problem.

The mass of the beam acts at the mid point, so apply mg at 21", and the force at 12" must be such that the moment at 21" is exceeded by the moment at 12".

The moment is a normal force * moment arm (length).

Since the problem imposes a force at 45° to the beam, then one must determine the component normal (perpendicular) to the beam. Similarly, as the beam rotates upward, the normal component of the weight changes because the axis of the beam is rotating in the gravitational field.

This problem belongs in the Engineering, Technology, . . homework section.
 
Astronuc said:
This is simply a moment problem.

The mass of the beam acts at the mid point, so apply mg at 21", and the force at 12" must be such that the moment at 21" is exceeded by the moment at 12".

The moment is a normal force * moment arm (length).

Since the problem imposes a force at 45° to the beam, then one must determine the component normal (perpendicular) to the beam. Similarly, as the beam rotates upward, the normal component of the weight changes because the axis of the beam is rotating in the gravitational field.

This problem belongs in the Engineering, Technology, . . homework section.


Thanks! Thats what I thought (moment problem). After I typed it out I started wondering if I was overthinking it Thanks again, I appreciate the help.
 
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