Question

A hydraulic lift has two pistons: 3 cm and 5 cm. A 1875 kg mass is lifted. Find force on small piston. \( g = 10\ \text{m/s}^2 \)

• A. 1250 N
• B. 125 N
• C. 6750 N
• D. 675 N

Hint:

In hydraulic systems, pressure remains constant: \( \frac{F}{A} = \text{const} \).

Answer 1

The Correct Option is C

Use Pascal’s law: \[ \frac{F_1}{A_1} = \frac{F_2}{A_2} \Rightarrow F_1 = F_2 \cdot \frac{A_1}{A_2} \] \[ F_2 = 1875 \cdot 10 = 18750\ \text{N} \Rightarrow \frac{r_1^2}{r_2^2} = \left(\frac{3}{5}\right)^2 = \frac{9}{25} \Rightarrow F_1 = 18750 \cdot \frac{9}{25} = 6750\ \text{N} \]