4B10.20 Mixing Hot & Cold Water

Use as example of what happens when you bring objects at different temperatures in contact and as example of irreversible process. Slowly add hot water until full. The top part will turn green where the water mixes.

Setup Requirements:Assembled as needed. You will need to allow time for hotplate to heat up and heat water.Color hot water with yellow food coloring. Color cold water with blue food coloring. Fill cylinder about 2/3 full with cold water.

Equations: Q = mc (delta T)

Safety Issues: Hotplate and hot water

4B20.10 Convection Tube

Demonstrate heat transfer by by convection. Observe color spreading through the water as the warmer water stars moving.

Setup Requirements: Assembled as needed. Fill with water. Heat one corner of lower part of tube using a candle. Add small amount of food coloring.

Equations: None

Safety Issues: Flame

4B20.20 Two Chimney Convection Box

Smoke is used to indicate convection in a two chimney box.

Setup Requirements: Minimal

Equations: None

Safety Issues: Flame

4B20.25 Candle in Tube (Symmetry Breaking and Convection).

If a lit candle is covered with a long tube it will go out. All the oxygen near candle is used up. Rising hot gases prevent more air from coming in. Put a divider in middle of tube and try again. There is so much air flow it blows flame around. Some small random difference converts symmetric situation into one with hot gases going up one side and fresh air going down other side of tube.

Setup Requirements: Minimal

Equations: None

Safety Issues: Flame,Smoke

4B30.21 Heat Transfer by Conduction Using Metal Strips

Demonstrate heat conduction. Put end of device in hot water. A strip along device changes color as temperature changes. Compare thermal conductivity of steel, brass, copper & aluminum.

Setup Requirements: Some assemble required. Allow time for water to heat to boiling point. May want to turn on hot plate at start of class.

Equations: None

Safety Issues: Red hot hotplate

4B30.22 Conduction Through Glass

Demonstrate heat conduction. Hold lower bulb in your hand. Heat will cause pressure and volume of gas to increase. Fluid will move up into top of device.

Setup Requirements: Minimal

Equations: None

Safety Issues: Fragile glass container. Do not squeeze tightly. Do not give to students.

4B30.23 Conduction in Metal vs Foam

Put ice cubes on two nearly identical blocks. One will melt much faster. One block is aluminum painted black to look like other material. Other material has low heat conductivity.

Setup Requirements: Minimal. Ask ahead of time so ice will be available. Take a towel to wipe water off desk.

Equations: Talk about Q=mc(delta T), Q=mL, and conductivity. Heat conduction depends on type of material.

Safety Issues: None

4B30.50 Frost on LN Cannon

LN is placed in the bottom of the LN cannon. Frost will form starting at the bottom and extending up the tube. Use as demo of heat transfer by conduction.

Picture: Not Yet Available

Setup Requirements: Minimal. Ask at least 1 day ahead of time so LN will be available or bring your own LN.

Equations: None

Safety Issues: Liquid Nitrogen

4B40.15 Heat Transfer by Radiation

Demonstrate heat transfer by radiation by focusing bright light on bottom of device. The heat will cause the air pressure and volume to increase and force a colored liquid up a tube into top of device.

Setup Requirements: Assembled as needed. Ask ahead of time

Equations: None

Safety Issues: hot light bulb, fragile glass device

4B40.40 Good Absorbers & Good Emitters

Demonstrate that good absorbers are good emitters. Put hot water in a silver can and a black can. Record temperature. Keep checking and recording temperature. The black can should cool faster.

Setup Requirements: Minimal. Fill cans in Demo Room.You will need time to heat up water and take measurements. Suggest doing something else while letting water cool.

Equations: Radiative cooling depends on surface and fourth power of temperature (Kelvin). 

Safety Issues: red hot hotplate, hot water

4B50.20 Heating Water in a Balloon

Demonstrate high heat capacity of water. Burn one balloon filled with air. Heat a second balloon filled with water.

Setup Requirements: Minimal

Equations: None

Safety Issues: Flame. Keep water filled balloon away from electronic devices on front desk.

4B60.10 Heating Lead Shot

Measure temperature of lead shot. Put in tube and shake tube of lead shot back and forth about 50 times.Measure temperature after shaking. The effect is small (~1 deg C). Use digital thermometer.

Setup Requirements: Minimal. Need digital thermometer. Tube has changed from that in picture.

Equations: None

Safety Issues: Wash hands if touch lead.

4B60.15 Kinetic Energy to Heat

Put a piece of paper over large metal ball and hit it with the other ball. Enough kinetic energy will be converted to heat to burn a hole in paper. In smaller classes do several times and pass paper around so students can smell that paper is burned not just torn.

Setup Requirements: Minimal

Equations: Kinetic Energy converted to heat (Q = mc deltaT).

Safety Issues: Dropping heavy balls.