Monday, 8 September 2014


                                 HEAT RADIATION

1.   You have two saucepans with hot soup inside them. One is shiny and the other is black. Which will cool down faster and why?

2.   When you switch on an electric light the bulb itself becomes very hot but does not melt. How does heat radiation help it to loose heat energy?

3.   How do the shiny sides of a vacuum flask help to keep a cold drink cold on a hot day?

4.   Why do fire fighters wear a suit with a shiny metallic surface?

5.   Would you feel hotter on a sunny day in a shiny black car or a filthy dirty white one? Why?

6.   At the end of a marathon the runners are often given shiny capes to put on. Why?

7. Why is it more likely to be a frosty night in winter if the sky is clear?

8. Venus is closer to the Sun than the Earth and has a very thick atmosphere. Explain what conditions would be like on the surface of the planet.

9. What type of surface will emit heat radiation best?

10. The "heat sinks" on electronic circuit boards are painted black. Why?