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Energy Introduction
1
Energy
What do you think of when you
hear this word?
What is Matter?
• Matter is anything that takes up space or has mass.
• Everything that is in this room is matter.
–Desk, chairs, posters, folders, water, air
• There are four states of matter:
–Solid
–Liquid
–Gas
–Plasma
• All matter is made of atoms.
Energy
• Energy is the ability to do work on or cause
change in matter.
• Everything has energy!
–It moves cars along the road
–It’s the sound of footsteps
–It’s the warming of your desktop when your hand
touches it.
Energy and its Forms
• Energy is found in many different forms
including:
–chemical, electrical, heat/thermal, light,
mechanical, nuclear, sound, etc.
• As you can see, there are many forms of
energy, but they can all be put into two main
categories:
–Kinetic & Potential
Kinetic Energy
• Kinetic Energy- the energy of movement.
–Example: A person jogging at a park.
• If something is in motion, it has kinetic energy.
• What has kinetic energy in these pictures?
Potential Energy
• An object still has energy even if
its not moving.
• Potential Energy- energy of
position or stored energy
Potential
–Ex. A glass of water sitting on the
edge of a table. While sitting there it
has stored energy because of its
position.
–If it is nudged, it can fall to the floor
and has energy of motion.
Kinetic
Potential Energy
• If something is not currently
in motion but has the
potential to be in motion at
some point, it has potential
energy.
• Which of these pictures
represents potential energy?
Potential Versus Kinetic Energy
• Think of all the forms of kinetic and potential
energy you would see in the following
situation: AT A PARK
Potential Versus Kinetic Energy
• Think of all the forms of kinetic and potential
energy you would see in the following
situation: AT SCHOOL
Experiment: Does mass affect
potential and kinetic energy?
• Think of the following situations:
–Rolling a bowling ball down the alley versus rolling a
volleyball down the alley.
–Two people of different weights racing down a hill
on a sled.
Experiment: Does ramp height affect
potential and kinetic energy?
• Think of the following situation:
–Riding a bike down Ginger Ridge Drive versus
riding down the hill in the parking lot.
Energy Lab
1. Question: Does mass & ramp height affect potential and kinetic
energy?
2. Use What I Know
3. Hypothesis: Write one of the following sentences.
I believe ramp height
I believe ramp height
I believe mass has no
increases the amount decreases the amount
effect on the amount of
of energy an object
of energy an object
energy an object has.
has.
has.
Write one of the following sentences.
I believe mass
I believe mass
I believe ramp height
increases the amount
decreases the
has no effect on the
of energy an object
amount of energy an
amount of energy an
has.Materials:
object has.
object has.
4. ExperimentDesign (paragraph or picture): ramp 6 & 9 inches, finish line 5 feet away
from bottom of ramp
Constants: I need to keep the following things the same in the
experiment to make it fair…
Energy Lab
5. Data:
Test 1- Car with no added mass, Ramp Height- 6 inches
Trial 1 Time:
Trial 2 Time:
Trial 3 Time:
Average:
Class Average:
Test 2- Car with added mass, Ramp Height- 6 inches
Trial 1 Time:
Trial 2 Time:
Trial 3 Time:
Average:
Class Average:
Test 3- Car with no added mass, Ramp Height- 9 inches
Trial 1 Time:
Trial 2 Time:
Trial 3 Time:
Average:
Class Average:
Energy Lab
7. Conclusion:
Based on your results, write one of the following sentences.
– Mass increases the amount of energy an object has because
the car with more mass went faster.
– Mass decreases the amount of energy an object has because
the car with more mass went slower.
– Mass had no effect on the amount of because both cars went
the same speed.
Based on your results, write one of the following sentences.
– Ramp height increases the amount of energy an object has
because the car went faster on the steeper ramp.
– Ramp height decreases the amount of energy an object has
because the car went slower on the steeper ramp.
– Ramp height had no effect on the amount of because both
cars went the same speed.
Self Check
• Do you understand kinetic versus potential
energy? Answer the questions about the
energy of the ball as it rolls from point A to
point G.
Being held at point
A (Not in motion)
Gaining speed
Losing speed
Types of Energy
Mechanical EnergyType of Kinetic and Potential Energy (Both)
•Definition:
The amount of work an object can do
because of its kinetic and potential energies.
•Example:
A rolling bowling ball has __________
energy (one type of mechanical energy) and the
stationary pins have __________ energy (another
type of mechanical energy) When the ball strikes the
pins, its energy is transferred to the pins. Now both
the ball and the pins have __________ energy.
•Other
information:
•Mechanical
•ALL
Energy= Kinetic + Potential Energy
MATTER HAS MECHANICAL ENERGY
Chemical EnergyType of Potential Energy
•
Definition: Chemical energy is energy stored
in the bonds of atoms and molecules.
•
Examples: Batteries (Power various objects,
Petroleum (Fuels our cars), Natural gas
(Fuels fireplace), Coal (Fuels factories), Wood
(Fuels fire), Food (Provides energy for our
bodies)
•
Other Information:
❖
THINK OF FUEL
•
Chemical energy is converted to other
forms of energy when we burn/use these
things.
Nuclear EnergyType of Potential Energy
• Definition: Nuclear energy is energy stored in the
nucleus of an atom.
• Example: Occurs in nuclear power plants, atomic
bomb, sun/stars
• Other information: Large amounts of energy can be
released when the nuclei are combined or split apart.
Electrical EnergyType of Potential Energy
•
Definition: Electrical energy is energy
stored in moving electrons.
•
Example 1: Power in power lines and
outlets provide electricity to many things
in the home.
•
Example 2: Lightning is an example of
electrical energy in nature.
•
Example 3: Static
Thermal EnergyType of Kinetic Energy
•
Definition: Thermal energy is the vibration and
movement of the atoms and molecules within a
substance.
•
Examples: Ice melting, water turning to steam,
oven cooking food, etc.
•
Other Information:
❖
As an object is heated up, its atoms move
faster and spread apart. As an object is
cooled, its atoms move slower come closer
together.
❖
THINK HEAT (OR LACK OF HEAT)
Radiant EnergyType of Kinetic Energy
•
Definition: Radiant energy is the movement of light
or electromagnetic waves.
•
Examples: Radiant energy includes sunshine,
other visible light forms, x-rays, etc.
❖ Other
Information: THINK LIGHT
❖ Travels
in waves
Acoustic EnergyType of Kinetic Energy
•
Definition: Acoustic energy is energy produced by
an object’s vibrations.
•
Examples: stereo playing, birds chirping,
clapping, etc.
•
Other information
❖
THINK SOUND
❖
Travels in waves
EXAMPLES OF ENERGY:
What type(s) of energy are being shown?
1. Roasting marshmallows
EXAMPLES OF ENERGY:
What type(s) of energy are being shown?
1. Roasting marshmallows
Thermal energy because the fire is
producing heat.
Radiant energy because the fire is
producing light.
Chemical energy because wood is
fueling fire.
Acoustic energy because the fire
“crackles.”
Mechanical energy because some
things are moving and others are not.
EXAMPLES OF ENERGY:
What type(s) of energy are being shown?
2. Eating breakfast then going for a jog
EXAMPLES OF ENERGY:
What type(s) of energy are being shown?
2. Eating breakfast then going
for a jog
Mechanical energy she is in
motion.
Chemical energy because
the food is giving her energy.
Acoustic energy because
she is making noise while
chewing and running.
Thermal energy because her
body is producing heat.
EXAMPLES OF ENERGY:
What type(s) of energy are being shown?
3. Food being cooked in the microwave
EXAMPLES OF ENERGY:
What type(s) of energy are being shown?
3. Food being cooked in the
microwave
Electrical energy because the
microwave uses electricity.
Thermal energy because the food is
being heated.
Radiant energy because the
microwave produces light.
Mechanical energy because some
things are in motion and others are still
Acoustic energy because microwave
makes sound.
Chemical energy because the food will
provide energy for a person.
Energy Transformations
Can energy appear or disappear?
No! It just changes forms.
An energy transformation is when energy
changes from one form to another.
Law of conservation
of Energy
Energy is neither created nor destroyed.
In other words, energy is transformed from
one type of energy to another, but the total
amount of energy remains the same.
Examples of Energy Transformations
•
When you speak into your telephone
acoustic energy from your voice is
changed into electrical or chemical
energy. (A phone plugged into the wall
uses electrical energy. A cell phone that
is not plugged into the wall runs on
chemical energy.) The energy is carried
through telephone wires. It is then
converted back into acoustic energy on
another phone, allowing someone to
hear you. The total amount of energy is
constant throughout this process.
Examples of Energy Transformations
•
To turn on a ceiling fan, you must
use mechanical energy to flip on
the switch. Then electrical
energy is transferred back into
mechanical energy and radiant
energy (if the fan has a light).
Again, the total amount of
energy remains the same.
Self Check
Check your understanding by answering the
questions from
http://www.poweringourfuture.com/students/
energy/.