Question

A piston of cross-sectional area $100c{m}^2$ is used in a hydraulic press to exert a force of ${10}^7$ dyne on the water. The cross-sectional area of the other piston which supports an object having a mass of 2000 kg is :

• A. $100c{m}^2$
• B. ${10}^{9}c{m}^2$
• C. $2\times {10}^{4}c{m}^2$
• D. $2\times {10}^{10}c{m}^2$

Answer 1

The correct option is C $2\times {10}^{4}c{m}^2$

As we know , 1 dyne = ${10}^{-5}$ N so ${10}^7$ dyne = 100 N

hence , for Hydraulic press we have

$\frac{100N}{100c{m}^2}$ = $\frac{2000g}{A}$ $\Rightarrow$ Area = $2\times {10}^{4}c{m}^2$

So option C is correct.