Heating and thermal equilibrium
Students often think that some materials (metals, water) are intrinsically cold, while others (plastic, wood) are intrinsically warm. These resources help students to develop a deeper undestanding of heat transfers and link to the following areas of the curriculum:
• heating and thermal equilibrium: temperature difference between two objects leading to energy transfer from the hotter to the cooler one, through contact (conduction) or radiation; such transfers tending to reduce the temperature difference: use of insulators.
The list provides a range of activities, lesson ideas, film clips, careers resources, background information, practical tips and suggested teaching strategies.
Links and Resources
There is a good poster about temperature in this resource, but it's the poster on the difference between accuracy and precision that is really useful here! It's a difficult concept for students to grasp, so this visual representation will help students to start to use the terms appropriately.
This inspiring careers clip is an ideal introduction to the topic of heat transfers and thermal insulation, showing the application of these concepts in building design.
In addition to illustrating the careers in which physics plays a part, the film also explains concepts such as heat transfer, conduction, convection, radiation and thermal conductivity.
Most students will tell you that heat energy travels from hot places to cold places. This simple yet profound demonstration will challenge them to think more deeply about this simple concept since the block that feels colder melts the ice more quickly.
This demonstration is a good opportunity for teachers to use plenty of open questions to guide students' thinking and to develop scientific vocabulary.
Thermal conduction involves energy flowing from a higher temperature to a lower temperature, and as a result the temperatures tend to become equal. Because thermocolour film makes variation in temperature visible, it is ideal for showing how energy moves along a conductor due to a temperature difference.
You could set up the most appropriate of these quick and visual demonstrations around the room for students to try. Recommended are the activities which show conduction, insulation, feeling hot and cold, and radiation.
Non specialists or those teaching the topic for the first time will appreciate the background science provided for each activity.
This resource, originally developed for Key Stage Four students, has been adapted for students working at levels 3-6, which makes it accessible for students in Key Stage Three.
Where Does All the Energy Go? (page 32 of the pdf document) is a particularly good piece of experimental work for encouraging students to think about energy transfers. A beaker of hot water is placed in a beaker or bowl of cold water and the temperatures of both are monitored over time. Where does the heat energy in the hot water go? The temperature drop of the hot water will not match the temperature rise of the cold water, why not? Has one lost more energy than the other has gained?
In the first part of this podcast, scientists discuss whether bubbles keep your bath warmer for longer. They explore how the bubbles in a bath could reduce water evaporation as well as heat loss by radiation and convection.
This can be used as an introduction to an investigation of heat transfer and insulation, with good scope for addressing areas of working scientifically.
This resource has two useful sets of worksheets to support lower ability students when investigating heat transfer:
Temperature and heat
Activities using a liquid crystal film to clarify students' understanding of the distinction between the terms hot, cold, heat energy and temperature.
A set of short activities which continue to explore the scientific ideas behind thermal insulation and to distinguish between heat and temperature. An extension activity allows students to investigate the idea of work done against friction transferring heat energy.
This activity challenges students to apply their understanding of heat transfer to the context of designing insulation for the Beagle 2 Lander.
The lander relies on batteries to carry out experiments, but the batteries' ability to supply energy is severely impaired by low temperatures.
The challenge can be differentiated to suit the ability of the students by adapting the criteria: “The temperature of the space probe should not drop below X degrees over a period of Y minutes.”
Since there was an absolute limit to the mass of the real Beagle 2, every gram that was used to protect the scientific payload was a gram that was effectively lost from that payload. To reflect this, the winning team must meet the criteria for heat loss whilst using the least mass of insulation.