Page 244 - Science Course 3 (Book 1)

Mo7-L1b: What are the Forms of Energy?

Key Concept FORMS OF ENERGY

What are the Forms of Energy? Sound Energy

How is energy related to work? When you pluck a guitar string, the string vibrates
and produces sound. The energy that sound car-
ries is Sound Energy. Vibrating objects emit sound
energy. However, sound energy cannot travel
through a vacuum such as the space between
Earth and the Sun.
Mechanical Energy

The total energy of an object or group of object
due to large-scale motions and interactions is
called Mechanical energy. For example the
mechanical energy of basketball increases when
a player shoots the basketball. However, the
mechanical energy of a pot of water does not
increase when you heat the water.
Electric Energy

An electric fan uses another form of energy-
electric energy. When you turn on a fan, there is an
electric current through the fan’s motor. Electric
energy is the energy that an electric current
carries. Electric appliances, such as fans and
dishwashers, change electric energy into other
forms of energy.
Nuclear Energy

At the center of every atom is a nucleus. Nuclear
energy is energy that is stored in the nucleus of an
Let’s Begin atom. In the Sun, nuclear energy is released when
nuclei join together. In a nuclear power plant, nu-
clear energy is released when the nuclei of urani-
um atoms are split apart.
Energy and Work
Thermal Energy
All energy can be measured in joules (J).
All objects and materials are made of particles
that are always moving. Because these particles
move, they have energy. Thermal Energy is ener-
gy due to the motion of particles that make up
Energy a object. Thermal energy moves from warmer
J = Joules objects to colder one. When you heat objects you
transfer thermal energy to those objects from their
surroundings.
Power Time Radiant -Light Energy
W = Watts t = Seconds
The Sun gives off energy that travels to Earth
as electromagnetic waves. Unlike sound waves,
electromagnetic waves can travel through vacuum.
Light waves, microwaves, and radio waves are all
electromagnetic waves. The energy that electro-
J J J magnetic waves carry is radiant energy. Some-

times radiant energy is called light energy.
W t W t W t
J = W x t W = J t = J
t W
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