Core Practical: Investigating Thermal Radiation Flashcards
All 6 cards in this deck
What are the steps to investigate how the nature of a surface affects the thermal energy radiated?
e.g. comparing a matt black can with a shiny silver can
- Fill each can with the same volume of water at the same starting temperature, e.g. cm at °C.
- Measure the temperature of each can at regular intervals with a thermometer or temperature sensor, e.g. every s for minutes.
- Compare the cooling: the matt black can cools fastest, so it is the better emitter.
In the cooling-cans experiment on thermal radiation, name three control variables.
Volume of water, starting temperature of the water, and the size/shape of the containers (also same surroundings and same room temperature).
What is the main safety precaution when investigating cooling using hot water?
Take care with the hot water and kettle to avoid scalds — stand containers on a stable surface away from the edge.
True or false? A shiny silver surface is a better absorber of thermal radiation than a matt black surface.
False. Matt black surfaces are the best absorbers and emitters; shiny silver surfaces are the worst.
Give two improvements to the cooling-cans thermal radiation experiment.
Use lids on the cans (so energy is lost mainly by radiation) and repeat the experiment to find a mean; a datalogger gives more frequent, reliable readings.
True or false? A surface that is a good absorber of thermal radiation is also a good emitter of thermal radiation.
True. A matt black surface both absorbs and emits thermal radiation better than a shiny silver one.