Question

The foot pedal on hydraulic brake system exerts a force of 45 lb on a piston with a diameter of 1.00 cm. The brake fluid in the brake system exerts the pressure from the foot pedal on a brake pad piston with a diameter of 2.50 cm. The force on the brake pad is:______
a. 133 lbs
b. 150 lbs
c. 281 lbs
d. 350 lbs
e. 402 lbs

Answer 1

Answer:

the correct answer is C,   281 lb

Explanation:

This is an exercise in fluid mechanics specifically on Pascal's principle, which states that the pressure in a fluid is equal to all points that are at the same depth

             P = $\frac{F_{1} }{A_{1} }$ = $\frac{F_{2} }{A_{2} }$

If we use the subscript 1 for the piston diameter mentor (d = 1.00vm) which is r = 0.05 cm, the force is F1 = 45 lb

          F₂ = \frac{F_{1} }{A_{1} }  F₁

in area of ​​a circules

         A = π r²

we substitute

          F₂ = $\frac{r_{2}^2 }{r_{1}^2} F_{1}$

let's calculate

           F2 = 2.50² / 1.00²  45

           F2 =281  lb

therefore the correct answer is C