Question

Data taken from a certain speed camera outside of Front Street and shows that traffic speed S, in mph, varies as a function of the traffic density q(in cars per mile) at that point on the road.

What is the practical meaning of the quantity S’(120). Give a brief but complete one or two sentence explanation that is understandable to someone not familiar with calculus

Answer 1

s(q) is the speed
s'(q) is the change in speed
so s'(120) is how fast the speed is changing when the density is 120 cars/mile