Download 10 - Solon City Schools

Chapter 13 Energy
& Power
How is energy important to us?
1
Energy



2
The ability to do work
or cause change is
called energy.
Works is the transfer
of energy.
Two types of energy:
 Kinetic energy is
energy of motion.
 Potential energy is
energy of position
or shape.
Forms of Energy







3
Mechanical energy
Chemical energy
Nuclear energy
Electrical energy
Electromagnetic
energy
Thermal energy
Acoustical energy
Which form of energy is sound?
10
Seconds
Remaining
acoustical
chemical
electrical
thermal
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rm
ica
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ch
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ac
o
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th
e
D.
al
C.
ric
B.
el
ec
t
A.
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Forms of Energy
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Mechanical energy is
the energy associated
with the motion or
position of an object.
Thermal energy is the
total energy of the
particles in an object.
Chemical energy is the
potential energy stored
in chemical bonds that
hold chemical
compounds together.
Forms of Energy



6
Electrical energy is
moving electric
charges produce
electricity and energy.
Electromagnetic
energy travels in
waves and have both
electrical & magnetic
properties.
Nuclear energy is
energy stored in the
nucleus of an atom and
is released during
nuclear reactions.
Forms of Energy

7
Accoustical energy
is energy of sound.
What type of energy is produced
from a battery?
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15
0%
...
lp
.
he
ee
d
En
er
gy
0%
In
So
la
r
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ne
...
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ne
...
rg
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10
ric
E.
0%
El
ec
t
D.
ica
le
ne
C.
10
m
B.
Chemical energy
Electrical Energy
Mechanical
Energy
Solar Energy
I need help. I
don’t understand.
Ch
e
A.
16
17
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What energy is required to operate this
device?
Electrical energy
Chemical Energy
Mechanical
Energy
Thermal Energy
Help!
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0%
En
H
el
e.
..
En
al
al
15
0%
p!
0%
er
gy
0%
m
Th
er
ic
al
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e
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ct
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ni
c
D.
M
ec
ha
C.
En
er
g.
..
B.
10
en
e.
..
A.
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What is the type present in the
sun?
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Ch
e
Ki
n
et
l
ric
a
ct
Ele
1
0
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0
17
0
..
0
ic
0
..
E.
Id
on
’t
kn
ow
D.
Nu
cle
ar
C.
ica
l
B.
Electrical
Kinetic
Chemical
Nuclear
I don’t know. I need
help.
m
A.
10
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What type of energy is dependent
on the height of an object?
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t. .
.
0
te
n
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15
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0
0
Ki
n
et
ic
Id
on
’t
kn
ow
..
..
21
6
st
ic
5
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4
po
lp
ot
3
m
ica
2
Ch
e
1
0
..
0
en
.. .
E.
l.
D.
io
na
C.
ta
t
B.
Chemical potential
Elastic potential
Gravitational
potential
Kinetic
I don’t know. I need
help.
Gr
av
i
A.
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:10
Kinetic Energy
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

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12
Remember, kinetic
energy is energy of
motion.
KE=½(mass x velocity2)
Doubling the mass,
doubles the kinetic
energy.
Double the velocity,
quadruple the kinetic
energy.
Potential Energy




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13
Elastic potential energy
is energy stored when
an object is stretched or
compressed.
Gravitational potential
energy is energy stored
because of the height of
the object’s position.
Chemical potential
energy is energy stored
in the bonds between
atoms.
GPE= weight x height.
Energy is measured in
units called Joules.
At what point(s) does the swinging
pendulum have the most kinetic energy?
10
A
B
C
D
Help!
A.
B.
C.
D.
E.
0
0
A
B
0
C
0
0
D
H
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p!
el
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At what point(s) would the swinging
10
pendulum have the most potential energy?
A.
B.
C.
D.
E.
A
B
C
D
Help!
0
A
0
0
B
0
C
0
D
H
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p!
el
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What is the relationship between
potential and kinetic energy?
A.
B.
C.
D.
There is no relationship.
As PE increases, KE
increases.
As PE increases, KE
decreases.
As PE decreases, KE
decreases.
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3
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5
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0
Th
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e
er
is
no
l
re
io
at
A
15
s
p
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ns
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es
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10
Which of the following devices
transforms electrical energy into
acoustic energy?
e
ab
of
th
e
ft
he
N
on
e
ll
o
A
0
ab
ov
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od
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0
G
ui
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r
D.
ric
C.
ec
t
B.
I-P
Electric Guitar
Radio
I-Pod
All of the above
None of the above
A.
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Joe Shmoe turns on a flashlight. Which
of the following lists the energy
10
transformations in the system?
A.
B.
C.
D.
Electrical  chemical 
mechanical  radiant
Chemical  electrical  thermal
 mechanical
Nuclear  chemical  electrical
Mechanical  chemical 
Electrical  radiant
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In which units do we measure
energy?
:10
4.
0
0
ki
lo
g
jo
gr
am
ul
e
0
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0
ew
to
n
3.
N
2.
gram
joule
kilogram
Newton
ra
m
1.
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When you wind up a rubber :10
band on an airplane, what type
of energy does this represent?
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5
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er
gy
0
tic
in
e
G
ra
v
ita
K
tio
n
en
po
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t
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ne
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ia
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e
lp
10
El
4.
0
m
ic
a
3.
he
2.
Chemical potential
energy
Elastic potential
energy
Gravitational
potential energy
Kinetic energy
C
1.
16
17
18
19
20
Which type of energy is
illustrated by a ball rolling down
a hallway?
1.
2.
3.
4.
Chemical
potential energy
Elastic potential
energy
Gravitational
potential energy
Kinetic energy
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2
3
4
5
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23 2124
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0
C
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h
a
ic
em
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ot
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ra
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at
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ti.
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tic
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Energy Conversion and
Conservation


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22
A change from one
form of energy to
another is called
energy conversion.
Most forms of energy
can be converted into
any other form.
What is the energy
conversion of the
flashlight in the
diagram on the right?
Energy Conversion

23
What is the energy
conversion for the
fan in the diagram
on the right?
Conservation of Energy

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Law of
conservation of
energy states that
when one form of
energy is converted
to another, no
energy is destroyed
in the process.
According to the
law of conservation
of energy, energy
cannot be created
or destroyed.
Fossil Fuels

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
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Fossil fuels are formed
from the burying of
plants and animals.
Include coal, petroleum
and natural gas.
Fossil fuels contain
energy that came from
the sun.
Fossil fuels can be
burned to release the
potential chemical
energy stored millions of
years ago.
Work


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Work is exerting a
force on an object,
causing it to move.
W=Fxd
Work is measured
in joules.
Power


Power is the rate at
which work is done or
the amount of work
done in a unit of time.
Power is calculated by
dividing the amount of
work done by the
amount of time taken
to do work.



27
Power =
work/time
Power = force x
distance/time
Power is
measured in
watts.
What happens to the energy as
a pendulum is started at its
:10
highest dropping point?
Kinetic changes to
potential.
Potential changes to
kinetic.
Potential equals
kinetic.
There is no change
between kinetic and
potential.
1.
2.
3.
4.
0
K
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2
3
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5
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25
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ic
et
in
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ch
ge
an
P
s
to
en
ot
15
0
..
p.
lc
tia
n
ha
s
ge
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to
en
ot
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0
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le
tia
a
qu
ls
T
17
k
et
in
re
he
0
.
ic
is
no
18
ch
ge
an
...
19
20
What is the proper energy
conversion that take place :10
when turning on a flashlight?
1
2
3
4
5
21
22
23 2924
25
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7
8
9
10
11
12
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15
em
ic
a
al
tr
ic
er
m
al
to
ch
el
ec
to
er
m
al
Th
16
0
l.
.
.
al
..
em
ic
ch
lt
o
ric
a
ec
t
El
14
0
..
0
...
tri
ca
l
ec
el
lt
o
m
ic
a
4.
0
he
3.
C
2.
Th
Chemical to electrical
to thermal.
Electrical to chemical
to thermal.
Thermal to electrical
to chemical.
Thermal to chemical
to electrical.
1.
17
18
19
20
Which of the following types
of energy is not a fossil fuel?
:10
Coal.
Hydroelectric.
Natural gas.
Petroleum.
1.
2.
3.
4.
0
C
oa
l.
H
1
2
3
4
5
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22
23 3024
25
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0
y
o
dr
ric
ct
e
el
15
0
.
N
16
a
ur
at
a
lg
17
0
s.
P
m
eu
l
ro
et
18
.
19
20
Pendulum Lab

Purpose: The
purpose of this lab is
for the students to
learn which factor
affects the period of
the swing of a
pendulum.

Materials:




31

3 different weights
meter stick
string
stopwatch
ring stand
Pendulum Lab

1.
2.
3.
4.
32
Procedure:
Tie a weight to the end of a string.
Attached the other end of the string to the
ring stand.
Pull the weight back a standard distance
and release the weight.
Time how long it takes for ten cycles of the
pendulum. Enter this data on the data
table.
Pendulum Lab
5.
6.
7.
8.
33
Divide the time by ten to find the time
for a single swing.
Change the weight and repeat
procedures 1-5.
Change the weight and repeat
procedures 1-5.
Next change the length of the string
and keep the weight the same.
Repeat procedures 1-5.
Pendulum Lab
9.
10.
11.
34
Change the length of the string a second
time and keep the weight the same.
Repeat procedures 1-5.
Change the angle of release. Repeat
procedures 1-5.
Change the angle of release. Repeat
procedures 1-5.
Pendulum Lab

1.
2.
3.
35
4.
Questions:
Make a drawing of the pendulum. Indicate
on the diagram the positions of the
maximum potential energy and the
maximum kinetic energy.
What were the variables in this
experiment? Which was the manipulative
variable and which was the responding
variable?
Explain how the Law of the Conservation of
Energy is observed in this experiment.
What forces act on the pendulum to stop its
motion?
Pendulum Lab

36
Look at the diagram on
the right.
Formative Assessment
Review

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






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37
What are the two types of energy?
(kinetic and potential)
Which type of energy is energy of motion?
(kinetic)
Which type of energy is stored energy?
(potential)
Which type of energy is stored in a stretched
rubberband or compressed spring?
(elastic potential energy)
Which type of energy is stored because of the position
of the object?
(gravitational potential energy)
Formative Assessment
Review

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







38
What is the formula for calculating kinetic energy?
(KE=mv2/2)
What is the formula for calculating gravitational
potential energy?
(GPE=w x h or GPE=m x g x h)
Name seven forms of energy.
(mechanical, thermal, chemical, electrical,
electromagnetic, nuclear, acoustic)
Which law states that energy is neither created or
destroyed?
(Law of Conservation of Energy)
What is the formula for calculating Power?
(P=w/t)
Formative Assessment
Review
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







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
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39
What unit is power measured?
(watt)
What unit is work or energy measured?
(joule)
What do we call the ability to do work or cause
change?
(energy)
What happens to kinetic energy if the mass is
doubled?
(doubles)
What happens to kinetic energy if the velocity
doubles?
(quadruples)
_______________ is the transfer of energy.
(work)
Formative Assessment
Review










40
What is the numerical value of gravitational
acceleration?
(9.8 m/s2)
What energy is associated with motion or position?
(mechanical)
What energy is associated with the total energy of the
particles of an object?
(thermal)
What energy is associated with the potential energy
stored in chemical bonds?
(chemical)
What energy is produced by moving electric charges?
(electrical)
Formative Assessment
Review
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







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41
What energy travels in waves?
(electromagnetic)
What energy is stored in the nucleus of an atom?
(nuclear)
What is it called when an energy form changes to
another form of energy?
(converstions)
Who stated that energy can be created by destroying
matter?
(Einstein)
How is energy released from fossil fuel?
(burning)
Formative Assessment
Review








42
What energy is mechanical energy converted to by
friction?
(thermal)
Name three fossil fuels.
(coal, petroleum, natural gas)
_______________ is the rate at which work is done.
(power)
How many watts are in one horsepower?
(746)