The volume of a cylinder is increasing at a rate of $10\pi$ cubic meters per hour.
The height of the cylinder is fixed at $5$ meters.
At a certain instant, the volume is $80\pi$ cubic meters.
**What is the rate of change of the surface area of the cylinder at that instant (in square meters per hour)?**
[[☃ radio 1]]
*The surface area of a cylinder with base radius $r$ and height $h$ is $2\pi r^2+2\pi r h$.*
*The volume of a cylinder with base radius $r$ and height $h$ is $\pi r^2h$.*