Chapter 6.CR, Problem 7CR

To determine

(a)

To find:

The meaning of $\frac{dA}{dt}$ in practical terms.

To determine

(b)

To find:

The meaning of $\frac{dA}{dt}$ being zero for a period of time.

To determine

(c)

To find:

If $\frac{dA}{dt}$ is negative or positive when the helicopter is coming down for landing.