Question

Define the term source of heat with any three source of heat

Answer 1

Temperature System

A heat source is anything that can heat up a spacecraft. Heat sources can be external (from outside the spacecraft) or internal (from inside the spacecraft). External heat sources include: the Sun. reflected sunlight from planets and moons.

In the end, if you're wondering where the heat in your home comes from, it's almost certainly one of the three main sources: combustion, electric resistance, or the outdoor air, ground, or water.