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Zorluk: ZorLevers and Fulcrums

A sheet metal fabricator uses a custom compound lever tool to punch holes in aluminum panels. The tool consists of two connected levers:

1. The Handle (Lever A): A second-class lever with its fulcrum at the very top. The handle is 25 inches25\text{ inches} long overall. A vertical connecting rod is attached to this handle 5 inches5\text{ inches} away from the fulcrum.
2. The Punch Arm (Lever B): A first-class lever positioned horizontally. The connecting rod pulls down on one end, which is 8 inches8\text{ inches} away from its fulcrum. The punching die is located on the opposite side of the fulcrum, 2 inches2\text{ inches} away.

If the fabricator applies a perpendicular force of 24 lbs24\text{ lbs} to the extreme end of the handle, what is the total downward force, in pounds, exerted by the punch die onto the aluminum panel?

Cevap: 480 lbs

Cevap

The correct answer is 480 lbs480\text{ lbs}.
In a compound lever system, the mechanical advantage of each lever multiplies sequentially to produce the final force. The handle (Lever A) provides a mechanical advantage of 25/5=525/5 = 5. Therefore, the 24 lbs24\text{ lbs} input is multiplied by 55, becoming 120 lbs120\text{ lbs} of force on the connecting rod. The punch arm (Lever B) provides a mechanical advantage of 8/2=48/2 = 4. The 120 lbs120\text{ lbs} input to Lever B is then multiplied by 44, resulting in a total output force of 480 lbs480\text{ lbs} at the punching die.

Adım Adım Çözüm

1
Calculate the input torque generated by the fabricator on Lever A.
24 lbs×25 inches=600 in-lbs24\text{ lbs} \times 25\text{ inches} = 600\text{ in-lbs}
Torque is determined by multiplying the applied force by the perpendicular distance from the fulcrum.
2
Determine the force exerted on the connecting rod by Lever A.
600 in-lbs/5 inches=120 lbs600\text{ in-lbs} / 5\text{ inches} = 120\text{ lbs}
In equilibrium, the input torque equals the output torque. The rod is attached 5 inches5\text{ inches} from the fulcrum.
3
Calculate the input torque on Lever B caused by the connecting rod.
120 lbs×8 inches=960 in-lbs120\text{ lbs} \times 8\text{ inches} = 960\text{ in-lbs}
The connecting rod applies 120 lbs120\text{ lbs} of force at a distance of 8 inches8\text{ inches} from Lever B's fulcrum.
4
Calculate the final output force at the punching die.
960 in-lbs/2 inches=480 lbs960\text{ in-lbs} / 2\text{ inches} = 480\text{ lbs}
The punching die is 2 inches2\text{ inches} from the fulcrum, balancing the 960 in-lbs960\text{ in-lbs} of torque on the opposite side.

Anahtar Kavram

Compound Lever Systems and Torque Balance
Tahmini Süre:1m 30s
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