a man 1.9 meters tall walks away from a light 2.4m above the ground. if his shadow lengthens at a rate of 0.6 m/s, how fast is walking?
as always, draw a picture If the distance from the pole is x and the shadow length is s, then
(s+x)/2.4 = s/1.9
x = 0.263s
so, since x is 0.263 as big as s at all times, it grows at that same scale factor; so the man's walking speed is 0.263 * 0.6 = 0.16 m/s