Unit 4: Radiation Flashcards
What is Radiation?
Radiation is the transfer of heat energy by electromagnetic waves.
What are electromagnetic waves?
Special waves that can carry heat energy.
What’s a Vacuum?
A space where there is no matter.
How does the sun’s energy get to earth?
The sun’s heat energy travels across empty space to the Earth through radiation.
How is Radiation different from other types of heat transfer?
Radiation transfers heat energy by waves, not matter.
It does not require physical contact or movement of particles, it can move through a vacuum.
How does radiation work through a braai?
The meat on the braaistand gets toasted or cooked through the transference of heat from the red-hot coal through radiation.
Give the definition of absorbtion.
Think ⚡️➕🌳🔜🔥
The process in which light strikes a surface and disappears, giving it’s energy to the surface in the form of heat.
Which colours absorb heat and which do not?
⬛️ Black objects absorb radiation very well, therefore they heat up quickly. 🏃🏿♀️
⬜️White & ◻️ silver reflect radiation waves, therefore they heat up slowly. 🐌
