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. 27.3 kPa

B. 3.43 kPa

C. 4.90 kPa

D. 68.6 kPa

Answer;

B. 3.43 kPa

Explanation;

Pressure is given by the formula;

Pressure = Force / Area

Force is the product of mass and acceleration due to gravity.

Thus; Force = mass x acceleration due to gravity

Substituting;

Force = (350 kg) x (9.8 m/s²)

Force = 3430 N

Then, using the first equation;

Pressure = 3430 N / 1m² or Pa

= 3.43 kPa