4. Energy, in physics, the capacity for doing
work. It may exist in potential, kinetic,
thermal, electrical, chemical, nuclear,
or other various forms. There are,
moreover, heat and work—i.e., energy in
the process of transfer from one body to
another.
6. • Heat energy is defined as a form of energy
which transfers among particles in a substance
(or system) by means of Kinetic energy of those
particles. In other words, under kinetic theory,
the heat is transferred by particles bouncing into
each other.
• In physical equations, the amount of heat
transferred is usually denoted by the symbol Q.
8. • The biggest example of heat energy in our solar system is the sun itself. The sun radiates
heat to warm us up on the planet earth.
• When the burner of a stovetop is very hot, it is a source of heat energy. Anything placed
onto the stovetop and warmed, whether a pot of tea or a skillet for frying eggs, also
become sources of heat energy.
• Any fire, from the smallest match, to the fireplace, to the biggest forest fire ever, contains
heat energy – with even the smallest of fires potentially resulting in the massive amount of
heat energy seen in a huge blaze.
• When ice is placed into a glass of water, the heat energy from the water eventually melts
the ice, meaning the water itself is a source of heat energy.
• Your body contains heat energy that can warm a cold glass of lemonade, melt the ice on
the other side of a window, and make someone else warm when you hug them.
• Geothermal energy is a type of heat energy generated and stored beneath the surface of
the Earth. This type of energy is used to heat homes and buildings.
• A huge amount of heat energy is stored in a bolt of lightning, which can strike and start a
fire or cause an electrical outage.
• Heat energy is contained inside of a hot piece of pizza – if it doesn’t cool down, that heat
energy has the potential to hurt the roof of a person’s mouth.
• When your computer is turned on, the components inside of it generate heat energy, which
needs to be cooled with a small fan installed within the machine.
• A bathtub filled with hot water contains enough heat energy to warm a cold body back to a
comfortable level on a frigid day.