Question

Which of the following quantities has the same S.I. unit as that of pressure?

(a) Work

(b) Energy / Velocity

(c) Energy / Displacement

(d) mass X (velocity)^2/Volume

I got this question at a job interview.

Question is taken from Fluids Mechanical Properties Pressure topic in portion Mechanical Properties of Fluids of Physics – Class 11

Answer 1

The correct choice is (d) mass X (velocity)^2/Volume

Best explanation: The S.I. unit of pressure is N/m^2.

Work has the unit of Nm. Energy/Velocity has the unit of Nm/(m/s)  = Ns.

The unit of energy/disp is Nm/m = N.

The unit of mass X (velocity) ^2/Volume is same as that of energy per unit volume because                                           mass X (velocity)^2 is equal to energy,

which is in turn equal to Nm/m^3 = N/m^2,                                                                                                                             therefore this is the correct option.