Question

In a hydraulic lift, used at a service station, the radius of the large and small piston is in the ratio of 20 : 1. What weight placed on the small piston will be sufficient to lift a car of mass 1500 kg?

• A. 3.75 kg
• B. 37.5 kg
• C. 7.5 kg
• D. 75 kg

Answer 1

The correct option is A 3.75 kg

Using pascal's law
$\frac{F_1}{A_1}=\frac{F_2}{A_2}$
$\frac{1500}{\pi r_1^2}=\frac{W}{\pi r_2^2}=\frac{1500}{{20}^2}=\frac{W}{1^2}$
$W=3.75kg$