Transcript Chapter 5 Section 1: What is Energy?

Chapter 5
Section 1: What is Energy?
Energy
Energy is the ability to do
work
Work is done when a force
makes an object move or
change its direction.
Example
When you kick a soccer ball, you are
doing work on the ball and then the
ball does work on the goal.
When one object does work
on another, energy is
transferred.
Energy is expressed in the
units Joules (J)
Kinetic Energy
Kinetic energy is the energy
of motion
Kinetic energy is the energy
of motion
All moving objects have
kinetic energy.
Kinetic energy depends on
mass and speed
Kinetic energy= mv2/2
M=mass
V2=velocity2
To increase kinetic energy,
increase the mass(m) or
speed(v) of the object.
Potential Energy
Potential energy is the
energy an object has
because of its position
There is more potential
energy in a car on top of a
hill than a car on a flat
street.
Gravitational potential
energy is a transfer of
energy to an object by
lifting it in the air.
Example
Holding a ball over your
head vs it resting on the
ground.
To calculate gravitational
potential energy:
Gravitational potential energy=
weight x height
Weight is the amount of
force needed to lift an
object and height is a
distance
Mechanical Energy
Mechanical Energy is the
total energy of motion and
position of an object
Mechanical energy=
potential energy+kinetic energy
Other forms of energy
• Thermal Energy
• Chemical Energy
• Electrical Energy
• Sound Energy
• Light Energy
• Nuclear Energy