OK. Kids have to make a hydrometer, using a straw, bluetac, and a couple of nails. They float it in water and mark off the spot on the straw, at the level of the meniscus.
Then they float it in a sample of flat soft drink (i.e. no bubbles adding to the flotation). Then they make sugar solutions using 1, then 2, then 3, etc teaspoons of sugar, and test the density of the solution each time. The aim is to determine how many teaspoons of sugar are in a can of soft drink.
Sounds simple, right? Wrong!
Today, I am going to try it using a diabetes urinoscopy hydrometer, (an
actual piece of laboratory equipment)and see if I can get results worth a damn.
Apparently, in other schools, kids had to write their report based on negative results - "Why this didn't work". Pretty mongrel sort of a thing to do to Yr9's I reckon. Whether they are bright and science-minded, or totally not interested, I think it is going to be an exercise in universal frustration, starting with ME!