A sheet of mass M moves with speed V through a region of space that contains particles of mass m and speed v. There are n of these particles per unit volume. The sheet moves in the direction of its normal. Assume m << M, and assume that the particles do not interact with each other.
(a) If v << V, what is the drag force per unit area on the sheet?
(b) If v >> V, what is the drag force per unit area on the sheet? Assume, for simplicity, that the component of every particle’s velocity in the direction of the sheet’s motion is exactly ±v/2.19