Answer:
Step-by-step explanation:
ignore the "at the instant the man is 30 feet away" part, set it as X and the man's shadow as Y.
Similar triangles so we can do .
Solve for it we get 44y = 6x
Differentiate relative to time t, we get 44y' = 6x'.
change in x (x') is equal to 5. And we get the answer y' = .
the ft/sec is the rate of which the length of the shadow is changing. add 5 to it for the rate of the tip of his shadow moving away from the tower.