Question

A man 6 feet tall walks at a rate of 13 feet per second away from a light that is 15 feet above the ground. When he is 8 feet from the base of the light, at what rate is the tip of his shadow moving?

Answer 1

HINT HINT: Use similar Triangles!

Answer 2

yup..gigles is right

Answer 3

another hint. the rate of change will be a constant, the "when he is 8 feet" will have nothing to do with it.

Answer 4

use
\[\frac{x}{6}=\frac{x+y}{15}\] to get a relation between x and y. you know
\[y'=13\] and you want
\[x'\]