Thermal Physics
Temperature and Internal Energy
Temperature is demonstrated by simulating molecular motion. Internal energy is demonstrated by heating water and by grinding a nail.
Click the image to watch the video
- Molecular motion simulator
- Thermometer
- Beaker of water
- Bunsen burner
- Support stand
- Nail
- Grinding wheel
A molecular motion simulator is used to demonstrate the microscopic concept of temperature. An increase in internal energy is demonstrated by heating a beaker of water and also by grinding on a nail.
Thermal Expansion
Thermal expansion is demonstrated by heating various solids.
Click the image to watch the video
- Ball and ring
- Bunsen burner
- Beaker of water
- Copper plate with hole
- Support stand
- Drill bit
- Propane torch
- Wet towel
- Bimetal strip
- Bimetal blinker
- 12-V battery
- Tail light
- Switch
Thermal expansion is demonstrated by heating a ball, a ring, a copper plate with a hole in it, and a bimetal strip. A blinker unit from an automobile is demonstrated as an application of thermal expansion of a small bimetal strip.
Change of Phase
Change of phase is demonstrated for melting ice, boiling water, and evaporation of water.
Click the image to watch the video
- Block of ice
- Thermometers
- Beaker of ice water
- Beaker of water
- Support stand
- Bunsen burner
- Mercury column barometer
- Vacuum system
- Balloon
- Sling psychrometer
- Humidity table
Ice is melted and water is boiled to demonstrate the concept of phase change. A vacuum system is used to demonstrate the effect of pressure on the boiling point temperature of water. Evaporation cooling is demonstrated and relative humidity is measured using a sling psychrometer.
Radiation
Heat transfer by radiation is demonstrated by reflection of infrared rays to a radiometer.
Click the image to watch the video
- Two concave reflectors
- Small heat radiator
- Radiometer
Energy from a small electric heater is reflected by concave reflectors to a radiometer. The radiometer is observed to respond by spinning.
Convection
Heat transfer by convection currents is demonstrated by heating air inside a vertical, hollow metal tube.
Click the image to watch the video
- Large Bunsen burner
- Hollow metal tube with wire mesh
- Safety gloves
- Paper strip slitted
Convection currents are demonstrated by heating the air inside a hollow tube. The direction of flow is observed using a slitted paper strip.
Conduction
Heat transfer by conduction is demonstrated for various materials.
Click the image to watch the video
- Copper rod on stand
- Wax rings (large and small)
- Bunsen burner
- Cup with heat sensitive painted surface
- Metal rods of differing conductivities
Heat conduction in a metal rod is demonstrated using melting wax rings. Also conduction is shown using a cup of hot water with heat sensitive paint on its outside surface. The relative conductivity of different metals is observed by timing the melting of small wax rings attached at a given distance from a common heat source.
Gas Law
The ideal gas law is demonstrated by varying the pressure, volume, temperature, and number of molecules of a gas (container of air).
Click the image to watch the video
- Pressurized air tank with release valve and gauge
- Pressure volume temperature apparatus
- Beaker of ice water
- Beaker of water
- Hot plate heater
- Thermometer
- Molecular motion simulator
The relationship between the pressure and the number of molecules is demonstrated using an air pressure tank. The relationships between pressure and volume, pressure and temperature, and volume and temperature are demonstrated using a special apparatus designed for observing the ideal gas law.
Expansion Cooling
Expansion cooling is demonstrated by allowing compressed air to suddenly expand.
Click the image to watch the video
- Large syringe
- Pressurized air
- Rubber hose
- Special glass flask
- Matches
Expansion cooling is demonstrated by observing fog formation inside a glass flask as the air pressure is suddenly released.