Infrared Radiation E-practical
Introduction
Infrared radiation is the radiation from the part of the electromagnetic spectrum just below visible light.
We feel the energy from this radiation as heat. We can feel this quite strongly when we face the sun but perhaps not so much in winter. We can also feel it from objects that are nowhere near as hot, such as a central heating radiator—which, due to the heating fluid being water, can never be more than 100 oC. A black surface is a better emitter and absorber than a white surface, which is one reason why tarmac can get very sticky in the summer sun and we readily feel the heat coming off a hot tarmac road. The tarmac is absorbing large amounts of the solar radiation and emitting it back to us.
Realistic experimental technique
E-practicals are 3d, highly realistic emulations based on a blend of theory and the actual practicals, giving an authentic experience of doing the actual practical in a laboratory. Students operate the apparatus, make measurements and obtain their own results. It is designed to reproduce the experience of performing the practical rather than simply demonstrating the underlying physics. Like a real experiment, it can be done badly. Careless setup or measurements can produce poor results, so students have to apply experimental technique and take care with their measurements.
Works directly in a browser
No installation is required. Windows, Mac and suitable mobile devices can run the WebGL e-practical.
See it in Action
This shows how the e-practical can be used. In particular it shows how the student or teacher interacts with the apparatus and how the interaction can be controlled using the mouse or the alternative on-screen controls.
What students do
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Fill the Leslie cube with hot water and wait a few minutes until all the surfaces have reached the same temperature. This can be checked by holding a thermometer against each surface.
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Place the thermometer at a fixed distance—say, 10 centimeters from the surface of the Leslie cube—and read the temperature. Note the surface facing towards the thermometer and the temperature.
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Repeat this for the other three surfaces as quickly as possible to prevent the water in the Leslie cube from cooling by more than a very small amount.
What you get
The application is supplied as a PowerPoint which provides background, a synopsis of what the student will learn, a description of the Physics involved, a description of the apparatus, the independent and dependent variables, the method, a link to the interactive online e-practical, analysis of the results and further discussion.
E-practical
Runs in a modern web browser. No software installation required. Recommended or desktops but will run successfully on tablets of medium to large size with a browser that supports WebGL.
School/Department licence £9.99
Valid for 1 year