charlie who is 6 feet tall walks away from a streetlight tha

charlie who is 6 feet tall, walks away from a streetlight that is 16 feet high at a rate of 6 feet per second, as shown in the figure. express the length s of charlies shadow as a function of time hint use similar triangles to express s as a functions of the distance d from the streetlight to charlie.

Solution

s / (s + d) = 6/16
Solve for s:
s = (3d / 5) ft

d = (t sec) x (6 ft/sec) = 6t ft

s = 3 (6t ft) / 5 = (18 t / 5) ft