The cavitation parameter σ of a centrifugal pump is mathematically expressed in terms of the Net Positive Suction Head (NPSH) and the net head (H). Which of the following formulas is correct?

The ratio of the specific weight of a liquid to the specific weight of a standard fluid is known as:

The magnitude of the buoyant force depends on the _____________.

In incompressible fluid dynamics, the continuity equation is ∂u/∂x + ∂v/∂y + ∂w/∂z = 0. What physical law does this equation represent?