DEMONSTRATION 9.4 Demonstration of Movement of Heat Through Radiation
Digital thermometer Perspex screen
Heat lamp
Fig 9.13
Apparatus Heat lamp, Perspex screen, digital thermometer
Procedure ■ Set up apparatus as illustrated in Fig 9.13. ■ Turn on the heat lamp and note any change in temperature. ■ Remove the Perspex screen and again note any change in temperature.
Observation There is a far greater rise in temperature when the Perspex screen is removed.
Conclusion We can tell that the heat travels from the lamp to the thermometer by radiation, because when the barrier (Perspex screen) is removed, there is a rise in temperature.
‘SECTION A’ EXPERIMENT QUESTIONS
Q1 The specific heat capacity of copper was found using an electrically powered heating coil. The following data was recorded.
mass of copper
initial temperature of copper final temperature of copper energy supplied
512 g
12.3 C 23.7 C 2 282 J
(i) Draw a labelled diagram of the apparatus used.
(ii) Using the data, calculate the specific heat capacity of copper (iii) Explain how an accurate measure of temperature was taken.
(iv) Give two other precautions that should be taken to ensure a more accurate result. 150 INVESTIGATING PHYSICS
