Question

A piston above a liquid in a closed container has an area of 1m2. The piston carries a load of 350 kg. What will be the external pressure on the upper surface of the liquid? A. 4.90 kPa B. 27.3 kPa C. 68.6 kPa D. 3.43 kPa

Answer 1

Explanation :

It is given that,

Area of the container, $A=1m^2$

Load carried by piston, m = 350 kg

Pressure on the upper surface of the liquid is defined as the force acting per unit area.

Mathematically it can be written as :

$P=\dfrac{F}{A}$

From Newton's second law of motion :

F = m a

So,  $P=\dfrac{mg}{A}$

$P=\dfrac{350\ kg\times 9.8\ m/s^2}{1\ m^2}$

P = 3430 Pa ( Pa = pascal)

or

P = 3.43 kPa

So, the correct option is (D)

Hence, this is the required solution.

Answer 2

I say the answere would be A