Transcript Conservation of Energy Potential and Kinetic Energy

Conservation of Energy
Potential and Kinetic Energy
Law of Conservation of Energy
aka. First Law of Thermodynamics
• the first law of thermodynamics is a
version of the law of conservation of
energy, adapted
for thermodynamic systems. The law of
conservation of energy states that the total
energy of an isolated system is constant;
energy can be transformed from one
form to another, but cannot be created
or destroyed.
TYPES OF
ENERGY
Mechanical,
Electromagnetic,
Electrical,
Chemical and Thermal
QUIZ TIME!
What type of energy
cooks food in a
microwave oven?
ELECTROMAGNETIC
ENERGY
What type of energy is
the spinning plate inside
of a microwave oven?
MECHANICAL ENERGY
QUIZ TIME!
Electrical energy is
transported to your house
through power lines.
When you plug an electric fan
to a power outlet, electrical
energy is transform into what
type of energy?
MECHANICAL ENERGY
QUIZ TIME!
What energy transformation
occurs when an electric lamp is
turned on?
ELECTRICAL ENERGY

ELECTROMAGNETIC ENERGY
What types of energy are shown below?
Mechanical and Thermal Energy
(Don’t forget friction)
What type of energy is shown below?
Chemical Energy
What type of energy is shown below?
Chemical Energy (yummy)
What type of energy is shown below?
Thermal Energy
Energy Transfer
Sound
(mechanical)
Thermal
Electrical
Mechanical
Chemical
Light
(Electromagnetic)
What are these for?
Potential
and Kinetic
Energy
How is all energy divided?
All Energy
Potential
Energy
Gravitation
Potential
Energy
Elastic
Potential
Energy
Kinetic
Energy
Chemical
Potential
Energy
What is Potential Energy?
o Energy that is stored
and waiting to be
used later
What is Gravitational Potential
Energy?
o Potential energy
due to an object’s
position
Don’t look down,
Rover!
Good boy!
o P.E. = mass x
height x gravity
What is Elastic Potential Energy?
o Potential energy due compression or
expansion of an elastic object.
Notice the ball compressing
and expanding
What is Chemical Potential Energy?
o Potential energy
stored within the
chemical bonds of
an object
Solving for Potential Energy
Potential Energy = mass x gravity x height
EP or PE = Potential Energy
EP = (m)(g)(h)
Find the gravitational potential energy of a light that
has a mass of 13.0 kg and is 4.8 m above the ground.
An apple in a tree has a gravitational potential energy
of 175 J and a mass of 0.36 g. How high from the
ground is the apple?
Solving for Kinetic Energy
Kinetic Energy = one half x mass x velocity squared
KE or EK = Kinetic Energy
EK = (1/2)(m)(V2)
What is the kinetic energy of a jogger with a mass of
65.0 kg traveling at a speed of 2.5 m/s?
A student is hit with a 1 kg pumpkin pie. The kinetic
energy of the pie 32 J. What was the speed of the pie