A person 1.8m tall is walking away from a lamppost 6m high at the rate 1.3m/s. At what rate is the end of the person's shadow moving away from the lamppost?
1 Answer
Jul 3, 2016
Explanation:
the point of what follows and the choice of variables in the drawing is this. we know that
so similar triangles tells us that
and now for the little bit of calculus, taking the deriv of each side with respect to time