Unit of mass velocity is

ANS:B - kg/m².hr

The unit of mass velocity is typically expressed as kg/hr. Mass velocity represents the mass flow rate, which is the amount of mass passing through a given cross-sectional area per unit time. It is commonly used in fluid dynamics, chemical engineering, and other fields where the flow of material is important. The unit kg/hr denotes the amount of mass (in kilograms) passing through a particular point or cross-sectional area per unit time (in hours). It's a straightforward and widely used unit for expressing mass flow rates.