Questions I Hope Our Students Can Ask

I also have a (tank-based) water heater in the basement.  This morning I washed some dishes (using the hot water) and then I wanted to make some coffee.

I have an electric caraffe that boils water.  It’s awesome.  You just put in some water, flip a switch, and soon your water is boiling.  I assume it heats up some element inside it, which heats up the water.

Should I fill the caraffe with hot water or cold water from my tap?

If I fill it with hot water, it takes some hot water out of my hot-water tank, which means that cold water goes into my hot-water tank (bad).  On the other hand, the electric caraffe doesn’t have to work as much to boil the water (good)!

If I fill it with cold water, the hot-water tank is left alone to be hot (good).  But my little caraffe has to work an extra 50 degrees! Also, the hotter my hot-water tank is, the faster it leaks heat into the cold basement air! Aiee!

I hope students coming out of my classes could

  • Understand the dilemma
  • Notice these dilemmas around them for themselves
  • Figure out what they’d need to know to answer the questions they have
  • Make an intentional decision about whether the work required to answer the question is worth having the correct answer to the question (instead of just shrugging it off because they don’t want to think about it).