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## Sources of Energy

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### Sources of Energy Ms. Angel s 3rd Grade Greenbriar West Elementary 2004-2005 Teaching Strategy Lecture Reinforce terms from handout provided by GBW Interactive ... – PowerPoint PPT presentation

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Title: Sources of Energy

1
Sources of Energy
• Greenbriar West Elementary
• 2004-2005

2
Teaching Strategy
• Lecture
• Reinforce terms from handout provided by GBW
• Interactive use handout as framework, not many
• marks the sheets the students will
get
• Lab
• Provide handout for lab groups to use
• Reinforce skills in observation, data collecting,
data plotting, and making conclusions

3
Topics
• Energy
• Mass and Force
• Potential and Kinetic Energy
• Electricity
• Renewable Energy Sources
• Nonrenewable Energy Sources

4
Energy
• Examine mass, force, and work as an introduction
to energy and power

5
Mass
• What is mass?
• Does a party balloon have more mass than a candy
bar?
• How do you figure out an objects mass?

6
Mass
• What is mass?
• Matter or stuff
• Does a party balloon have more mass than a candy
bar?
• Bring in one of each contrast size vs mass
• How do you figure out an objects mass?
• Weigh it but is mass the same thing as weight?
something is the same no matter what but its
weight varies

7
Force Key Points
• What is a force?
• Why does gravity exert a force on you?
• If an object is not moving does that mean that
there are no forces on it?

8
• What is a force?
• Something that pushes or pulls you
• Why does gravity exert a force on you?
• Two objects with mass attract each other
• If an object is not moving does that mean that
there are no forces on it?
• It may but it probably means that the forces
acting on an object cancel out

9
Forces
The man is standing still. Are there any
forces on the man? If so, draw them.
floor
10
Forces
The force due to gravity is the same in size, but
opposite in direction, to the force by the
floor!!!!
Gravity
Floor
11
Gravitational Force - Questions
• So what causes a gravitational force?
• Is there a gravitational force on the moon?
• Is it larger or smaller than the gravitational
force on the Earth?

12
• So what causes a gravitational force?
• Two objects are attracted to each other

Object 1 (has mass)
F1
F1 F2
F2
Object 2 (has mass)
13
Gravitational Force
• Gravitational force keeps us stuck to the
Earth!!!
• We actually pull on the Earth but the Earth is
too big to move!!!

Person
How much you weigh depends on your mass and the
mass of the planet you are on.
F
Fperson Fearth
F
Earth
14
Gravitational Force - Questions
• Is there a gravitational force on a person
standing on the moon?
• Is it larger or smaller than the gravitational
force on the Earth?
• Why?

15
• Is there a gravitational force on the moon?
• Is it larger or smaller than the gravitational
force on the Earth? yes
• The gravitational force is smaller on the moon
1/6 of the Earth.
• Why?
• The moon is smaller (1/6th the mass) than the
Earth.

16
How the Moon Causes Tides
• Since the water in the oceans are liquid they are
pulled out of shape by the moons gravitational
force
• Causes water level to rise thus creating tides
(i.e. water seemingly getting deeper and
shallower for no apparent reason)

Earth
Water bulging up
Moon
17
Weight vs Mass
• Weight is a force W m g
• m mass and
• g acceleration due to gravity 9.81 m/s2

PLOT THE DATA!!
180
m (kg) W (N)
10 98
5 49
12 118
5 52
18 177
5 47
8 78
160
140
120
100
Weight, N
80
60
40
20
0
0 2 4 6 8 10 12 14 16 18 20
Mass, kg
18
Weight vs Mass
• The slope of the plot is g 9.81 m/s2

180
X
m (kg) W (N)
10 98
5 49
12 118
5 52
18 177
5 47
8 78
160
140
120
X
100
X
Weight, N
80
X
60
X
X
X
40
20
0
0 2 4 6 8 10 12 14 16 18 20
Mass, kg
19
Break
20
Work
• Review Force is a push or a pull
• Exerting a force over a distance is WORK
• For example, pushing the desk across the room is
a lot of work

21
Potential and Kinetic Energy Key Facts
• What is energy?
• What is potential energy?
• What is kinetic energy?

22
Potential and Kinetic Energy Key Facts
• What is energy?
• Ability to do work
• Potential energy stored energy
• How can we store energy?
• Kinetic energy energy of movement
• How is potential energy converted into kinetic
energy?

23
Potential Energy
Does the ballhave any storedenergy here?
Does the ballhave any storedenergy here?
24
Potential Energy
Does the ballhave any storedenergy here?
Does the ballhave any storedenergy here?
YES, we moved the ballagainst gravity (did work)
NO
25
Potential Energy
What happens when we let go of the ball? If the
ball is to move show the direction of the
ball. Label the forces on the ball!!!!
26
Potential/Kinetic Energy
What happens when we let go of the ball? It
starts to fall has kinetic energy Convert
potential into kinetic energy If the ball is to
move show the direction of the ball. Label the
forces on the ball!!!! Gravity is larger force
than air resistance
Gravity
velocity
Air resistance
27
Quick Review of Science Facts
• Force is a push or pull
• Work is exerting a force over a distance
• Energy is the ability to do work
• Power is energy being used over a period of time

28
Introduction to Electricity
29
Electricity
• Electricity is a form of energy that starts with
atoms.
• Atoms are too small to see, but they make up
everything around us.
• An atom has three tiny parts  protons,
neutrons, and  electrons. The center of the atom
has at least one proton and one neutron. At least
one electron travels around the center of the
atom at great speed.
• Electricity is created by forcing electrons to
flow from atom to atom.
• What kind of energy is this?

30
• Electricity is a form of energy that starts with
atoms.
• Atoms are too small to see, but they make up
everything around us.
• An atom has three tiny parts  protons,
neutrons, and  electrons. The center of the atom
has at least one proton and one neutron. At least
one electron travels around the center of the
atom at great speed.
• Electricity is created by forcing electrons to
flow from atom to atom.
• What kind of energy is this?Kinetic energy
the electrons are moving

31
How Electricity is Generated
• Most electricity used in the United States is
produced at  power plants.
• Various energy sources are used to turn
turbines.
• The spinning turbine shafts turn electromagnets
that are surrounded by heavy coils of copper wire
inside generators.
• This creates a magnetic field, which causes the
electrons in the copper wire to move from atom to
atom.

32
Nonrenewable Energy Sources
33
Renewable vs Non-Renewable?
• What is a renewable energy source?
• What is a non-renewable energy source?

34
Renewable vs Non-Renewable?
• What is a renewable energy source?
• You can make more of it
• What is a non-renewable energy source?
• There is a limited amount of it and you cannot
make more of it

35
Break
36
Non-Renewable Energy Sources
• Give some examples of nonrenewable energy sources

37
Fossil Fuels
• The majority of electricity used in the United
States is generated from power plants that burn
fossil fuels (coal, oil, and natural gas).
• Why do we call these fossil fuels?
• Why does this make them nonrenewable?
• When the fossil fuels are burned they heat water
and make steam.
• The highly pressurized steam is directed at the
blades of turbines to make them spin.
• What type of energy conversion is this process?

38
Fossil Fuels
• The majority of electricity used in the United
States is generated from power plants that burn
fossil fuels (coal, oil, and natural gas).
• Why do we call these fossil fuels?
• Oil, coal, and gas are formed by many tiny
organisms being compressed (high heat and
pressure) by layers of sand and rock over the
years
• Why does this make them nonrenewable?
• It takes millions of years to create fossil fuels
• When the fossil fuels are burned they heat water
and make steam.
• The highly pressurized steam is directed at the
blades of turbines to make them spin.
• What type of energy conversion is this process?
• Potential into kinetic and kinetic into kinetic

39
Nuclear Energy
• Nuclear power plants use the heat from splitting
atoms to convert water into the steam that turns
turbines.
• These plants rely on uranium, a type of metal
that must be mined from the ground and specially
processed.
• Fuel rods containing uranium are placed next to
each other in a machine called a nuclear reactor.
• The reactor causes the uranium atoms to split and
in so doing, they release a tremendous amount of
heat.

40
Renewable Energy Sources
41
Renewable Energy Sources
• Give some examples of renewable energy sources
be creative!!!

42
Solar Energy
• Solar energy is generated without a turbine or
electromagnet. Special panels of photovoltaic
cells capture light from the sun and convert it
directly into electricity. The electricity is
stored in a battery.
• What type of energy conversion process is
happening here?

43
Solar Energy
• Solar energy is generated without a turbine or
electromagnet. Special panels of photovoltaic
cells capture light from the sun and convert it
directly into electricity. The electricity is
stored in a battery.
• What type of energy conversion process is
happening here?
• Kinetic to electrical

44
Wood
• Burn wood from trees to produce heat to create
steam by heating water which in turn power
turbines
• Wood is renewable only if trees are replanted and
grown as quickly as they are used
• Why is wood not normally used to make
electricity?

45
Wood
• Burn wood from trees to produce heat to create
steam by heating water which in turn power
turbines
• Wood is renewable only if trees are replanted and
grown as quickly as they are used
• Why is word not used to make electricity?Doesn
t create much heat (per lb) and is very messy

46
Grain Fuel - Ethanol
• Distill grain into a liquid fuel called ethanol
that can be used for cars and power plants
• Renewable source is simply grain (e.g. wheat,
barley, etc like those used in bread) can
always grow more
• Over 2 million cars per year in the USA already
are set up to run on E85 (85 ethanol and 15
gasoline)

47
(No Transcript)
48
Geothermal Power
• Steam (or hot water converted to steam) from
under the ground is used to turn turbines.
• Usually from geysers or hot springs
• Why might this form of energy not be used very
much?

49
Geothermal Power
• Steam (or hot water converted to steam) from
under the ground is used to turn turbines.
• Usually from geysers or hot springs
• Why might this form of energy not be used very
much?Not many hot springs and difficult to
pipe steam or hot water

50
Hydropower
• Hydroelectric plants use the power of falling
water to turn the turbines that help generate
electricity. Water stored behind a dam is
released and directed through special tubes to
flow against the blades of turbines and make them
turn.
• What type of energy conversion is taking
place?
• Hydropower provides about 10 percent of the
electricity generated in the United States.
• The most famous hydroelectric facility in the
country is Hoover Dam.

51
Wind Power
• Wind is usually created by uneven heating of the
earth
• The force of the wind is used to spin many small
turbines.
• Most wind power is produced from wind farms
large groups of turbines located in consistently
windy locations.
• Why might wind power be difficult to generate?

52
Wind Power
• Wind is usually created by uneven heating of the
earth
• The force of the wind is used to spin many small
turbines.
• Most wind power is produced from wind farms
large groups of turbines located in consistently
windy locations.
• Why might wind power be difficult to
generate?Some days it is not windy and the
windmills or turbines take up a lot of room

53
Wind and water power experiment(split class into
two teams)
• Water
• Pour a gallon of water each day into hydropower
plant
• Count turns of the wheel
• Plot the data
• Reuse water
• Make observations
• Wind
• Take wind power plant outside each day for one
hour
• Count turns of the gear
• Plot the data
• Make observations

54
Wind and Water Plots
Use W for wind and H for water (hydro)
10 8 6 4 2 0
Turns
1 2 3 4 5 6 7 8 9
10
Day
55
Wind and Water Plots(possible example results)
Use W for wind and H for water (hydro)
W
10 8 6 4 2 0
W
Turns
W
W
H
H
W
W
H
H
H
H
H
H
H
W
W
H
W
W
1 2 3 4 5 6 7 8 9
10
Day
56
Experiment Summary
• What would be the best way to produce energy
water or wind?