How Work Gets
What is Energy?
Energy is the ability to cause
Two General Types of
• Potential Energy
• Kinetic Energy
What is Potential
• Potential energy is
the energy stored in
– Chemical energy
stored in batteries.
– Mechanical energy
stored in a
spring, or tight
• Gravitational potential energy is the
stored energy of position.
– A rock on top of a hill has more
potential energy than the same rock at
the bottom of the hill because the rock
at the top has the added energy of
being in a position where gravity can
act on it longer.
Weight (N) = mass (kg) x gravity (9.8
What is Kinetic
• Kinetic energy is the
energy of motion.
• The faster something is
moving the more kinetic
energy it has.
• KE =(m x v2) / 2
Forms of Energy
What is Mechanical
• Mechanical energy is the
motion of objects.
• An example is the energy you
use to pick up a book.
What is Sound
• Sound energy
is the vibration
of particles in a
solid, liquid, or
• Sound can not
What is Electromagnetic
Electromagnetic energy is transmitted through
space in the form of electromagnetic waves.
• Electromagnetic energy is a combination of
electrical and magnetic forces.
– Visible light is a form of electromagnetic
energy, as well as x-rays and microwaves.
– The Sun releases large amounts of
electromagnetic energy, some of which is
absorbed by Earth.
What is Electrical
• Electrical energy comes from
the charges in atoms of
• Electrical energy is the force
of opposite charges (“+” and
–Lightning, static, and
current are forms of
What is Magnetic
• Magnetic energy comes from
the organization of atoms in a
• Magnetic energy is the force
of opposite poles (north and
What is Nuclear Energy?
What is Chemical
• Chemical energy is energy that is
stored in the chemical composition
• An example is the energy used by
cells in your body comes from the
What is Thermal
• Thermal energy, is the energy
from the movement of
Thermal Energy –
• Heat is the transfer of thermal energy
• Heat always flows from the warmer
objects to the cooler objects.
• Temperature is the measure of how fast
the molecules of a substance are
moving. The faster the molecules
move, the higher the temperature.
• Energy can not be created
• Energy can be transferred
from one form to another.
• One form of energy can turn into
• An example is when a ball is thrown
(mechanical energy) against a wall,
some of this energy is converted into
sound and heat so the ball does not
bounce back as far.
• Most energy that is “wasted” in a
transfer is converted to heat energy.
Batteries (chemical to electrical)
Electrical (electrical to electrical)
Lights flash (electrical to light)
Motor turns (electrical to mechanical)
Motor makes noise (mechanical to
• Motor gets warm (mechanical to heat)
• Wheels turn (mechanical to mechanical)
• Friction on floor (mechanical to heat and
• Wind - up
• Jack - in - the -