A gas flows through a horizontal pipe with a mass flow rate of 0.5 kg/s. The gas constant is 292 N·m/kg·K. At section 1, the cross-sectional area is 40 × 10-4 m2, the pressure is 50 × 104 N/m2, and the temperature is 15°C. What is the velocity of the gas at section 1?

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?