Define the following: radiant energy

1. Radiant heat: The heat energy transmitted through radiation, is called radiant heat.
2. Radiation: The process of transmission of heat from a hot object to a cold object in the absence of a medium is called radiation.
3. Radiant heat travels in a straight line with the speed of light (i.e., 3×10⁸ m/s).
4. Radiation is the fastest process of heat transfer.
5. For example, the earth receives radiant energy from the sun.