Question

Bernoulli’s principle is based on the law of conservation of:
A. Mass
B. Momentum
C. Energy
D. None of those

Answer 1

Hint: Bernoulli’s equation can help to identify the conservation law linked with Bernoulli’s principle. We are applying conservation law by assuming that no energy will lose during fluid flow. This is an ideal condition.
Formula used: $P+{\displaystyle \frac{1}{2}}\rho v^2+\rho gh=\text{a constant}$, here $\rho gh$ represents the potential energy, ${\displaystyle \frac{1}{2}}\rho v^2$ represents the kinetic energy and $P$ is the pressure energy.

Complete step-by-step answer:
Bernoulli’s principle can be defined as, In a steady flow of a fluid, the pressure of the fluid decreases at which the velocity of the fluid increases and vice versa. When an incompressible fluid is passing through different sized tubes, the speed of the fluid will change according to the size of the tube. As we know, the change in velocity indicates acceleration. According to Newton’s laws, acceleration occurs only because of the force. The pressure can be defined as the force over an area. So we can make a connection between velocity and pressure. Fluids will travel from higher pressure to lower pressure due to the acceleration.
If we are dealing with a non-viscous and incompressible fluid, then the work performed by the pressure, potential energy developed by the change in height of the fluid and kinetic energy will be added up and the sum will be constant. This leads to the conservation of energy.
$P+{\displaystyle \frac{1}{2}}\rho v^2+\rho gh=\text{a constant}$, here $\rho gh$ represents the potential energy, ${\displaystyle \frac{1}{2}}\rho v^2$ represents the kinetic energy and $P$ is the pressure energy.
So the correct option is C.

Additional information:
Aerodynamics is an application of Bernoulli’s principle. The shape of the aeroplane is designed for easy movement through the air. According to this design, the bottom of the plane will be flat while the top will be curved. Since the plane is moving through the air, air travels across the top and bottom of the aeroplane at the same time. In the flat region, air moves very slowly. That means this area is under high pressure. While the air at the top surface will move very fastly. That is it creates less pressure on the top side. The high pressure at the bottom will help to push the wings. Thus the aeroplane can lift. The air moves very fastly on the top of the aeroplane, and it helps for travel for long distances.

Note: The conservation of energy is an assumption only. Normally during the fluid flow, some energy will lose due to the internal friction. This property can be called viscosity. The kinetic loss due to the viscosity will turn into heat energy. That’s why we are applying Bernoulli’s equation ideally for incompressible non-viscous fluids. If we are taking compressible fluids, then we have to consider the elastic energy also.