3. Feeling Cool (Conduction)

PROBLEM

• Students investigate properties of materials and use their understanding of temperature to explain why different materials feel warmer or cooler than each-other.

CURRICULUM LINK

• Students observe the effects of heat moving from one object to another, eg the feeling when hands are placed on warm or cold materials
• Describes everyday interactions between objects that result from contact and non-contact forces

METHOD

1. Student scientists are divided into two groups:
   1. One (or more) 'hot' group(s) and one (or more) 'cool' group(s).
2. Student scientists create two very simple two-row tables - a 'hot' table and a 'cool' table
3. Students scientists set up materials on a table in the playground before recess.
4. Dureing recess, student scientists ask other students to touch each of the materials and state which material that they think feels coldest and which they think feels warmest.
5. Student scientists record their results in a table:
   1. Students scientist in the 'hot' group record the item that people say is warmest.
   2. Students scientist in the 'cool' group record what material people say is coolest.
   3. Both groups should measure the temperature of each item (using an infra-red thermometer) at the start and at the end of their experiment. The measured temperatures should be recorded in a third, separate table. For example:

Scientists in the 'hot' group ask: 'What item do you think feels WARMEST:' and enter the reply in a table

Scientists in the 'cool' group ask: 'What item do you think feels WARMEST:' and enter the reply in a table - In the top row, tick the box of the item people say is COOLEST:

The tables can simply be created and results entered using pen and paper, and then transferred later into a Google sheet.

OPTIONAL EXTENSION

• Create a Google form/sheet and have students enter data in real-time using iPad or similar mobile device

Students combine discuss/graph/analyse the results that they obtained. For example:

Discuss the results of your Heat Prediction Survey results (see example table above).

EXAMPLE QUESTIONS

1. Does a metal ruler feel colder or warmer than a wooden ruler?
2. What materials do most people think feels warmer or cooler?
3. Can we trust that the way things feel to us will be the same to someone else?
4. How can we find a way to agree about the temperature of different materials?
5. What does 'thermal equilibrium' mean
6. How can you check that the concept of 'thermal equilibrium' is correct?
7. Can you convince others that you are correct?

Some example answers:

• My results for Table 1 (above) show that most adults and students (66%) think that metal is colder than wood.
• When measured with a thermometer the temperature of metal and wood were … …
• This confirms the misconceptions that most people may have (as described in Video 1. above). Most people think….
• I think the reason that the metal and wood are the same temperature is because…

QUESTIONS

• What is 'radiation'
• What kid of stuff gets 'radiated'
• What things would you say 'radiate' stuff
• What is 'infra-red' and how can we use it to measure temperature?

DISCUSSION

• Share and compare you solution and convince others that your explanation is correct.

• IF UNABLE TO ACCESS YOUTUBE, TRY:Viewpure

• IF UNABLE TO ACCESS YOUTUBE, TRY:Viewpure

• IF UNABLE TO ACCESS YOUTUBE, TRY:Viewpure

• IF UNABLE TO ACCESS YOUTUBE, TRY:Viewpure

• DANCING MOLECULES IN LIQUIDS (3min)
• DANCING MOLECULES IN VAPOUR (3min)