4A10 - Thermometry

Show & Tell Thermometers (4A10.10) Various thermometer types including liquid (alcohol or mercury), bimetallic coil, liquid crystal, thermocouples, or IR.

4A20 - Liquid Expansion

Thermal Expansion of Water (4A20.10) A flask filled with colored water has a long glass tube protruding up from the neck. A gas flame is placed under the flask and thermal expansion forces water up the tube.

4A30 - Solid Expansion

Bimetallic Strip (4A30.10) Two different metal strips bonded together and fastened to a handle. When heated, the strip bends because of the different expansion rates of the metals.

Bimetallic Coil Same as the bimetallic strip, but helical in form. The coil is heated and moves a large indicator arrow as it expands.

Ball and Ring (4A30.21) A metal ball and ring on handles are constructed so that the ball will just pass through the ring at room temperature. The ball is heated and will not pass through the ring. The ball and ring are both heated and the ball now passes through the heated ring.

Ball and Hole (4A30.22) A ball which is too large to pass through a hole in a square metal plate will pass easily through the hole after the plate has been heated in a flame. Many students expect the hole to shrink upon heating, but it actually expands along with the rest of the plate.

4A40 - Properties of Materials at Low Temperatures

4B10 - Heat Capacity and Specific Heat

Ruchardt's Experiment for gamma (Cp/Cv) (4B10.70) A steel ball in a precision tube oscillates as gas escapes from a slightly overpressured flask. By measuring the oscillation frequency, you can determine the ratio gamma = Cp/Cv. Note: Please talk to us in advance.

4B20 - Convection

Convection in Square Tube (4B20.10) A large glass square loop is filled with water and heated by a burner near one bottom corner. The resulting circulating convection current is shown by adding drops of dye to the water.

Convection Currents Projection (4B20.40) Convection currents from a hot filament in a small water cell are projected onto a screen using a simple Schlieren optics system.

4B30 - Conduction

Thermal Conductivity (4B30.12) Five rods of different composition are attached to a steam chamber to provide equal temperatures at the bases of the rods. The rods are covered with wax, which melts and peels off as the rods heat up. Relative rates of heat conduction can be deduced from the rates at which the wax melts on each rod. The five materials in order of decreasing conductivity are: copper, aluminum, brass, steel, and glass.

4B40 - Radiation

Radiation from Hot and Cold Bodies Two parabolic reflectors are aligned facing each other, with a thermopile at the focal point of one of the reflectors and a heated sphere at the other. A projection galvanometer's deflection shows the transmission of heat by radiation. Replace the hot sphere with a sphere dipped in liquid nitrogen and the galvanometer will deflect in the opposite direction (showing that the thermopile itself is radiating and heat flows to the cold sphere).

4B50 - Heat Transfer Applications

Insulation (Dewar Flasks) (4B50.10) Four dewar flasks (thermos bottles) are filled with boiling water and a thermocouple is placed in each. Each flask has a different degree of insulation, and these are (from worst to best): unsilvered without vacuum between the walls, silvered without vacuum, unsilvered with vacuum, and silvered with vacuum. The water temperature is measured throughout the class period and compared to an uninsulated beaker. Temperatures are collected and displayed via a LabVIEW program and a laptop plugged into the projector.

4B60 - Mechanical Equivalent of Heat

Drill and Dowel (4B60.55) A wooden dowel held in an electric drill chuck is ground against a large flat piece of wood. The friction between the two produces heat and smoke.

Cork Popper (4B60.70) A motorized rotating hollow shaft holds a thimblefull of water and is sealed with a stopper. Wood brakes are squeezed together on either side of the rotating shaft, and the heat generated by friction boils the water and pops the cork.

4B70 - Adiabatic Processes

4C10 - PVT Surfaces

PVT Surface Model - Ideal Gas (4C10.10) A three dimensional model showing various PVT states of an ideal gas.

PVT Surface Model - Carbon Dioxide (4C10.10) A three dimensional model showing various PVT states of carbon dioxide.

PVT Surface Model - Water (4C10.10) A three dimensional model showing various PVT states of water.

4C20 - Phase Changes: Liquid - Solid

Thermite An extremely exothermic reaction between Iron Oxide (rust) and Aluminum produces liquid Iron.

4C30 - Phase Changes: Liquid - Gas

4C31 - Cooling by Evaporation

Drinking Bird (4C31.30) Commercial novelty item. Dip the bird's beak into a beaker of water, then let it go. Evaporation of the water from the wet beak cools the beak, lowering the vapor pressure of the liquid inside and drawing it up into the head. That overbalances the bird and it tips into the water for a "drink." In that position, the liquid inside flows back into the lower bulb, which rights the bird and starts the cycle over. Note: This is not very visable for a large class without using a camera.

4C33 - Vapor Pressure

Hand Boiler (Franklin's Pulse Glass) (4C33.50) A glass tube contains a small amount of a volatile liquid (Methylene Chloride). Heat from your hand will boil the liquid and the vapor pressure will force it to flow to the opposite end of the tube. Note: This is small and not very viewable for a large class.

4C40 - Sublimation

4C50 - Critical Point

Critical Point of CO2 (4C50.10) liquid CO2 in a glass tube at high pressure is close enough to the critical point that warm air from a hair dryer will complete the transition. The tube is displayed with a video camera and the meniscus is seen, but when the tube is heated the meniscus slowly fades and disappears as the liquid CO2 goes through a gradual transition to a high pressure gas. A turbulent mixture of liquid and gas with equal densities is seen above and below the miniscus point.

Critical Opalescence (4C50.20) A mixture of triethylamine and water is heated and passes through the liquid/gas critical point. The liquid is clear at first, then becomes cloudy as it approaches the critical point.

4D10 - Brownian Motion

4D20 - Mean Free Path

Crooke’s Radiometer (4D20.10) A partially evacuated glass bulb holds a pinwheel where the vanes are reflective on one side and painted black on the other. Light from an incandescent lamp will be absorbed by the dark side of the vanes, heating the nearby air, and causing the pinwheel to rotate towards the reflective side of the vanes.

4D30 - Kinetic Motion

4D50 - Diffusion and Osmosis

Bromine Diffusion (4D50.45) Two glass tubes containing bromine and bromine/air are cooled in liquid nitrogen and allowed to warm back up to show rates of diffusion. The bromine only tube will diffuse faster than the bromine/air mixture.

4E10 - Constant Pressure

Galileo's Thermometer (Thermal Expansion of Air) (4E10.11) Air expansion in a inverted glass bulb causes liquid level in a vertical tube below the bulb to drop.

4E20 - Constant Temperature

Boyle's Law (Pressure vs. Volume) (4E20.10) A syringe is connected to a dial pressure gauge. Compressing the syringe causes an increase in pressure.

4E30 - Constant Volume

4F10 - Entropy

Entropy Pennies A tray is filled with pennies painted green on the tails and red on the heads. If the tray is shaken the pennies begin to flip at a rate dependent on the magnitude of the shaking. Eventually an equilibrium is reached, with approximately equal numbers of reds and greens. Further shaking will not, of course, return them to their original state. If only a few pennies are used, they will occasionally return to their original state, showing the dependence upon the number of particles in the system.

Mixing and Unmixing (4F10.10) The volume between two coaxial cylinders is filled with glycerin and a thin column of red dye. When the inner cylinder is rotated, the dye appears to be mixed but is distributed in a fine cylindrical shell within the glycerin. Reversing the direction of inner cylinder rotation will cause the original dye column to reappear. Note: Please talk to us about this first.

4F30 - Heat Cycles

Heron's Engine (or Hero's Engine) (4F30.01) A working model of the first primitive steam engine. A glass globe containing a small amount of water is heated with a flame. The steam produced comes out through two arms and spins the globe.

Stirling Engines - General Information (4F30.10) Pick from the following selection. Or follow this link for general heat engine references.

Stirling Engine - Transparent Pistons Has glass cylinders so the power and displacement pistons can be viewed.

Stirling Engine - Hand Held A Stirling engine so well machined and balanced that it can run off the heat from your hand.

Stirling Engine - Heavy Duty A heavy duty Stirling engine. This is the biggest engine, but perhaps the least instructive because of low visibility.

Stirling Engine - Hot and Cold Will run in one direction when placed on a hot resevoir, and will run in reverse when placed on a cold resevoir. Note: May be out of service.