I teach calculus, pre-calculus, and physics. In physics today we were going over the homework problems in our section on buoyancy. This is a counterintuitive subject for some folks, so I’ve had a day of demonstrations (sinking or floating items of various sizes and shapes) and a day of labs (find the volume and weight of a container, calculate how much mass needs to be added to make it float at half it’s height, 90% its height, etc). Two days of lectures.

While working the homework problems, I’m greeted with stunned silence that I should expect 11th and 12th graders to be able to convert liters to cubic meters, or calculate the volume of a rectangular parallelogram. How much lower will a rectangular barge of known dimensions float if a 400Kg horse steps onto it? 1 Liter of water has a mass of 1Kg. Volume equals length times width times height.  I shouldn’t assume this is known?

“You haven’t taught this to us and now you expect us to know it for the quiz tomorrow? You aren’t doing enough teaching!” 

After class, I ask some of the students who I know have read the chapter if I’m going too fast. They answer in the negative. I also ask my wife if I’m being unreasonable. She answers in the negative.

It’s the complainers that set one’s teeth on edge. The ones who think they should be retaught their lessons from 5th grade (“that was so long ago”). I need a bit of venting, but many of my students make a good effort and want to learn the material – if only for grades.

I don’t have anyone in the physics class (or calculus or pre-calculus for that matter) who has an interest in science or engineering. It’s a challenge this year. I think I’m coming up with better lessons, but to what avail?

Of course, I have even less of an idea of what they will do in their lives than they do, so maybe this will be a useful introduction some day. Or it will just be Physics for Poets and Artists. It’s not a bad thing if they know what causes lightning and rainbows and why giraffes need huge hearts and a serious system of valves to keep from fainting whenever they lift their heads up from drinking water.

Okay, there’s peace in the valley. 

Now I’ll make up the quiz for tomorrow!