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Zorluk: KolayLevers and Fulcrums

A mechanic presses a brake pedal with a force of 25 pounds25\text{ pounds}. The pedal pivots on a hinge at the top. The mechanic's foot applies the force 16 inches16\text{ inches} from the pivot point. The brake's pushrod, which transfers the force to the master cylinder, is attached to the pedal 4 inches4\text{ inches} from the pivot point. Calculate the force, in pounds, applied to the pushrod.

Cevap: 100 pounds

Cevap

100 pounds
The brake pedal functions as a second-class lever. To find the force transmitted to the pushrod, use the principle of moments where Effort Force × Effort Distance = Load Force × Load Distance. By substituting the known values, we get 25 lbs×16 inches=Fload×4 inches25\text{ lbs} \times 16\text{ inches} = F_{\text{load}} \times 4\text{ inches}. Multiplying 2525 by 1616 yields 400 inch-pounds400\text{ inch-pounds} of torque. Dividing this torque by the load distance of 4 inches4\text{ inches} reveals that a force of 100 pounds100\text{ pounds} is applied to the pushrod.

Adım Adım Çözüm

1
Identify the known variables from the problem.
Effort Force = 25 lbs, Effort Distance = 16 in, Load Distance = 4 in.
Organizing the known values is the first step to applying the lever equation.
2
Apply the mechanical advantage principle for levers.
Effort Force × Effort Distance = Load Force × Load Distance
In a state of equilibrium, the torque applied by the effort must equal the torque applied to the load.
3
Substitute the known values into the equation.
25 × 16 = Load Force × 4
This sets up the equation to isolate the unknown load force.
4
Calculate the effort torque.
400 = Load Force × 4
Multiplying the effort force by its distance from the pivot gives the total torque in inch-pounds.
5
Solve for the final load force.
Load Force = 100
Dividing the total torque by the load's distance from the pivot gives the force applied to the pushrod.

Anahtar Kavram

Torque and Mechanical Advantage in Second-Class Levers
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