Question

In a car lift compressed air exerts a force $F_1$ on a small piston having a radius of $5cm$. This pressure is transmitted to a second piston of radius $15cm$. If the mass of the car to be lifted is $1350kg$. What is $F_1$?

• A. $14.7\times {10}^{3}N$
• B. $1.47\times {10}^{3}N$
• C. $2.47\times {10}^{3}N$
• D. $24.7\times {10}^{3}N$

Answer 1

The correct option is B $1.47\times {10}^{3}N$

From pascal’s law

$P_1=P_2$

$\frac{F_1}{A_1}=\frac{F_2}{A_2}$

$\frac{F_1}{\pi {r_1}^2}=\frac{F_2}{\pi {r_2}^2}$

$F_1=\frac{F_2{r_1}^2}{{r_2}^2}$

$F_1=\frac{1350\times 9.8\times {(5\times {10}^{-2})}^2}{{(15\times {10}^{-2})}^2}$

$F_1=1470N$

$F_1=1.47\times {10}^{3}N$