It’s that time of the semester… related rates have returned in calculus. I have taught related rates problems in Calculus for years, but have never really been sure whether the students get the whole concept. There are now some excellent demos on the internet to help them see the problems in motion.

First let me point you to a site called “Demos with Positive Impact” shown above. This is an NSF sponsored site that hosts ten different related rates problems.

Also, I found a few nice related rates problems on Wolfram Demonstrations:

So what’s missing? Would someone talented please do the inverted conical water tank problem or the searchlight problem as an animation? Or perhaps point me to where you’ve found them on the internet?