Question

Euler's equation is used to describe the motion of fluids under the influence of what forces?

• A. Pressure forces alone
• B. Gravitational forces alone
• C. Frictional forces alone
• D. Pressure and gravitational forces

Hint:

Euler's Equation of Motion. Describes ideal (inviscid) fluid flow. Relates acceleration to forces due to pressure gradient and gravity. Neglects viscous forces. Bernoulli's equation is derived from Euler's equation.

Answer 1

The Correct Option is D

Euler's equation of motion for fluids is derived by applying Newton's second law (\(F=ma\)) to an infinitesimal fluid element, considering it to be an ideal fluid (inviscid, meaning no frictional forces).
The forces considered in the derivation are:
(1) Pressure forces acting on the surfaces of the fluid element (due to the pressure gradient).

(2) Body forces acting on the volume of the element, primarily gravity.
The equation relates the acceleration of the fluid element to the pressure gradient and the gravitational force per unit volume.
Viscous (frictional) forces are explicitly neglected.
Therefore, Euler's equation considers pressure and gravitational forces.