Question:easy

Bernoulli's equation is conservation of

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Look at what each term in Bernoulli's equation, pressure head, velocity head and elevation head, physically represents.
  • Mass
  • Energy
  • Momentum
  • Angular Momentum
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The Correct Option is B

Solution and Explanation

Instead of memorising the name, derive Bernoulli's equation from first principles and see what physical law it comes from.

Consider a small fluid element moving along a streamline in an ideal, frictionless, incompressible flow. Apply Newton's second law along the streamline direction, this gives \(\dfrac{dp}{\rho} + v\,dv + g\,dz = 0\).

Integrating this along the streamline gives \(\dfrac{p}{\rho} + \dfrac{v^2}{2} + gz = constant\), or dividing through by g, \(\dfrac{p}{\rho g} + \dfrac{v^2}{2g} + z = constant\).

Each term here is a form of energy per unit weight, flow work (pressure energy), kinetic energy, and potential energy. The equation is really just a statement that the total mechanical energy of the fluid particle does not change as it moves, provided there is no friction and no external work is done on or by it.

\[\boxed{\text{Bernoulli's equation represents conservation of Energy}}\]
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