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Zorluk: KolayLevers and Fulcrums

A carpenter uses a claw hammer to pull a stubborn nail out of a wooden plank. The hammer head rests on the plank, creating a pivot point (fulcrum) that is exactly 2 inches2\text{ inches} away from the nail. The carpenter applies a perpendicular pulling force of 40 lbs40\text{ lbs} on the hammer's handle, at a distance of 12 inches12\text{ inches} away from the pivot point. Assuming the hammer acts as a simple first-class lever, how much upward force is exerted on the nail?

  1. A
    80 lbs80\text{ lbs}
  2. B
    200 lbs200\text{ lbs}
  3. 240 lbs240\text{ lbs}Cevap
  4. D
    480 lbs480\text{ lbs}

Cevap

The upward force exerted on the nail is 240 lbs240\text{ lbs}.
The claw hammer acts as a first-class lever where torque is balanced around the fulcrum. The formula for a balanced lever is Effort×Effort Arm=Load×Load Arm\text{Effort} \times \text{Effort Arm} = \text{Load} \times \text{Load Arm}. Plugging in the given values yields 40×12=Load×240 \times 12 = \text{Load} \times 2, which simplifies to 480=2×Load480 = 2 \times \text{Load}. Dividing both sides by 2 gives a load force of 240 lbs240\text{ lbs}.

Adım Adım Çözüm

1
Identify the lever arms for the hammer setup.
The effort arm (distance from the pulling hand to the fulcrum) is 12 inches12\text{ inches}. The load arm (distance from the nail to the fulcrum) is 2 inches2\text{ inches}.
Correctly identifying the distances from the fulcrum is necessary for calculating mechanical advantage and balancing torque.
2
Calculate the mechanical advantage (MA) of the lever.
MA=Effort Arm/Load Arm=12/2=6\text{MA} = \text{Effort Arm} / \text{Load Arm} = 12 / 2 = 6.
The mechanical advantage indicates how many times the lever multiplies the input force.
3
Calculate the total upward force exerted on the nail.
Force on nail=Effort force×MA=40×6=240 lbs\text{Force on nail} = \text{Effort force} \times \text{MA} = 40 \times 6 = 240\text{ lbs}.
The output load force is the product of the input effort and the mechanical advantage.

Anahtar Kavram

Mechanical Advantage and Torque Balance in First-Class Levers
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