(Solved): Suppose a police officer is 1/2 mile south of an intersection, driving north towards the intersecti ...

Suppose a police officer is $1/2$ mile south of an intersection, driving north towards the intersection at $50\mathrm{mph}$. At the same time, another car is $1/2$ mile east of the intersection, driving east (away from the intersection) at an unknown speed. The officer's radar gun indicates $35\mathrm{mph}$ when pointed at the other car (that is, the straight-line distance between the officer and the other car is increasing at a rate of $35\mathrm{mph}$ ). What is the speed of the other car? Speed $=\mathrm{mph}$. Now suppose that the officer's radar gun indicates $?35\mathrm{mph}$ instead (that is, the straight-line distance is decreasing at a rate of $35\mathrm{mph}$ ). What is the speed of the other car this time? Speed $=\mathrm{mph}$.