DL-Heat and Gas Laws
Demo - Ball and Hoop - Thermolinear Expansion. What happens when you heat just the ball? WHat happens when you heat just the hoop? (Kids will predict about 50 50 on this as to whether the hole in the hoop gets bigger or gets smaller when you heat it. I talk about cold riveting)
Demo - Bi-Metallic strip - Brass expands faster than steel, so the strip bends when the temperature changes. Thermometers and old thermostats used this.
Demo - Thermal Stress. I heat a non Pyrex test tube (because they are cheap, and we can't really use them in the classroom) and put it in cold water, and show the kids the tiny cracks from the thermal shock. I talk about the shadows people cast on marble buildings at Hiroshima when they protected the building from the blast from the bomb. I talk about Raku effect on clear glaze.
Demo - Ice Melter blocks - Put an ice cube on each of the two black blocks. On one (anodized Aluminium) the ice melts rapidly. On the other (plywood?) the ice melts only slowly. You can talk about thermal conductivity. Also - why when every object in a room is at the same temperature, do some things (metal things esp) feel so cold, and others not cold.
Demo - Natural Convection - The Convection box - show natural convection currents with smoke from touch paper.
Demo - Black Body Radiation - Show a red how paperclip using a step down transformer.
Lab - Absolute Zero lab - Using the Gay-Lussac's law apparatus I gather pressure and temperature data at room temperature, at the temperature of hot tap water, at the temperature of boiling water, and at the temperature of ice water. We extrapolate this to absolute zero. I focus on the proper data table, and the proper conclusion where they cite data. Since the needle is loose and wonky, I try to justify error bars at +/- 20 Torr. This makes them big enough for a max and min extrapolation. (The weights keep it balanced, and immersed)
The website is helpful:
Demo - Black Can Silver Can - the black and silver cans cool at different rates because they have different emissivity.
Demo - demo