Question
A person 6 feet tall walks at a rate of 150 feet per minute toward a light tower whose searchlight is located 40 feet above the ground. Find the rate that the length of the shadow is changing.
Answers
Steve
Draw a diagram. If the man is x feet from the tower, and his shadow is s ft long, then using similar triangles,
s/6 = (x+s)/40
s = 3/17 x
ds/dt = 3/17 dx/dt
...
s/6 = (x+s)/40
s = 3/17 x
ds/dt = 3/17 dx/dt
...