The radius of the base of a cylinder is decreasing at a rate of $12$ kilometers per second.
The height of the cylinder is fixed at $2.5$ kilometers.
At a certain instant, the radius is $40$ kilometers.
**What is the rate of change of the volume of the cylinder at that instant (in cubic kilometers per second)?**
[[☃ radio 1]]
*The volume of a cylinder with radius $r$ and height $h$ is $\pi r^2h$.*