4) Thermal Properties

a) Heat Capacity, Specific Heat and Latent Heat

An Example of an insulated container for heat experiments. Five equal mass balls of different metals are heated to 100 C and placed on a wax strip.
The balls that contain enough heat melt through the wax while the rest only partially melt
the wax.
Re-Heater for Latent Heat of Crystals
A supersaturated solution that releases heat when it becomes a crystal.
I need one-hour prior to prepare the solution. Heat water and a steel plate over the same flame to show how much higher in temperature
the steel is over the water. Shows the constant temperature during the time of phase transition.
The computer samples the temperature and plots a graph of temperature Vs time.
I need a day notice to prepare the ice and this runs about fifteen minutes in the back of
your lecture. Shows latent heat of water as it changes to steam.
The rag is soaked in a 50/50 solution of water and alcohol so it burns but does not harm
the rag.
  b) Liquid Nitrogen An acoustic heat engine with no moving parts.
A strong temperature gradient across closely spaced plates in the middle of the tube creates
a thermodynamic cycle of oscillating air.
Produces sound. A small glass cannon the fires a rubber stopper when a small amount of Liquid Nitrogen
is poured inside. A small light bulb is turned on until the battery chemical reaction slows down as it freezes
in liquid nitrogen. A rubber tube is placed inside liquid nitrogen that spouts nitrogen as boiling occurs inside
the tube. Small kit of an YBaCO Superconductor which lifts off a magnet. Drive frozen nails with a frozen banana (you supply the banana0 or show gas laws with
balloons cooled in liquid nitrogen.
Compare helium balloons to one blown by a person. c) Thermodynamics Ignites tissue paper with high pressure via adiabatic compression shows dU=dW if dQ=0 Shows adiabatic cooling of gas as it rapidly expands. A fluorescent dye is seemingly dispersed in a fluid filled container but then it opposes
entropy and forms back into a drop.
The fluid is glycerine so the dye actually just spreads out in layers. d) Conduction, Convection, and Radiation Five different metal rods are equally heated and wax indicators melt off their ends
depending on the heat conductivity of the metal. Paper is wrapped around a wood/metal joint and is then placed in a flame.
The paper over the metal does not burn due to conduction but the paper over the wood
burns quickly. A flat panel of liquid crystals that can visually show heat conduction down the panel. Two cups connected by a metal bar to conduct heat between them.
Thermometers show changes in heat (too small for lecture hall)                            A drop of dye is placed in a fluid filled glass tube.
                           As the tube is gently heated in one corner the dye indicates fluid flow and heat transfer
                           by convection. A box that has two openings and contains a candle.
Heat from the candle causes a convection current of air that can be seen with smoke. Closed glass bulbs shaped in odd ways and filled with a volatile fluid.
The fluid boils and rises quickly with the latent from your hand. A comical bird that operates by evaporative cooling to make it tip over and repeat the cycle. A light bulb-like device where black and white panels absorb radiation at different rates
thereby heating air molecules to different amounts.
The difference in heating causes the panels to rotate on a spindle. A Cube filled with hot water the radiates energy at a different colored sides.
A thermocouple and a digital voltmeter provides readings. A sensitive thermocouple that produces voltage when heated.
It can be used with the radiation cube or with a heat lamp and colored filters to
indicate spectrum. e) Thermocouples Shows voltage generated between two different metals as they are heated.
The voltage displayed on a digital voltmeter Shows cooling using electrical current. f) Thermal Expansion Shows thermal expansion as a ball slides through a ring.
If the ball is heated it will not pass through the ring but if both are heated it will pass. Shows the difference in the linear thermal expansion of two different metals. The strip bends
when heated. Disk Jumps when it cools and snaps into position. Lower temperature leads to contraction of a solid metal bar.
Shows length change with temperature change Steam Passes through a cooper tube and the linear expansion is shown on a dial. g) Engines Plastic models of various kinds of engines. Shows working hot air engine that operates close to the Cabot cycle. A Heat Lamp and Large hand boiler combined to create a useless heat engine.