Question

The blades of a windmill sweep out a circle of area A. If the wind flows at a velocity v perpendicular to the circle, then the mass of the air of density $\rho$ passing through it in time t is :

• A.
• B.
• C. $A v ^ { 2 } \rho t$
• D. $\frac { 1 } { 2 } \mathrm { Av \rho t }$

Answer 1

Answer: (A)

Answer 2

Volume of wind flowing per second = Av

Mass of wind flowing per second =

Mass of air passing in time t s =