Transcript Work Power Energyx

What
is the weight of a 5
kilogram apple sitting on a table?
(Hint: W = mg)
Agenda:
--notes over work & power
--practice solving story problems
 Givens:
5 kg = m
 Unknown = W
 Equation: W = mg
Do you remember what g is?
g = 9.8 m/s2
 Plug

in numbers:
W = mg
= (5 kg) (9.8 m/s2)
49 newtons
W = 49 kg ∙ m/s2
 Do
you remember what kg ∙ m/s2 equals?
NEWTON
Q: WHICH HUMAN BODY SYSTEM
TAKES IN OXYGEN AND GETS RID OF
CARBON DIOXIDE?
A. circulatory
system
B. muscular system
C. respiratory system
D. skeletal system
S.C.8.3.1.d DOK1
A: WHICH HUMAN BODY SYSTEM TAKES IN
OXYGEN AND GETS RID OF CARBON DIOXIDE?
circulatory system
The circulatory system contains blood, which
carries nutrients and oxygen to all parts of the
body.
B. muscular system
The muscular system allows the body to move.
C. respiratory system
The respiratory system brings oxygen into the
body and carries carbon dioxide out of the
body.
D. skeletal system
The skeletal system contains bones, which
supports the body and protects organs.
A.
S.C.8.3.1.d DOK1
Q: WHEN OBSERVING SEVERAL LIQUID
LAYERS IN A GRADUATED CYLINDER,
WHERE IS THE LEAST DENSE LIQUID?
A.
on the top
B.
in the middle
C.
on the bottom
D.
in the lightest-colored layer
SC8.2.1.g DOK 2
A: WHEN OBSERVING SEVERAL LIQUID
LAYERS IN A GRADUATED CYLINDER,
WHERE IS THE LEAST DENSE LIQUID?
A. on the top
The least dense liquid will rise to the top.
B. in the middle
The density of this liquid will be between the
least dense and the most dense liquid.
C. on the bottom
The densest liquid will settle on the bottom.
D. in the lightest-colored layer
Color does not determine the density of a liquid.
SC8.2.1.g DOK 2
1. Which product was
exported most in
the year 2004?
A. corn
B. rice
C. soy
D. wheat
2. Which product demonstrated the sharpest decline
in export and in what years?
A. rice from 2003 to 2004
B. rice from 2004 to 2005
C. corn from 2007 to 2008
D. wheat from 2007 to 2008
1. Which product was
exported most in
the year 2004?
A. corn
B. rice
C. soy
D. wheat
2. Which product demonstrated the sharpest decline
in export and in what years?
A. rice from 2003 to 2004
B. rice from 2004 to 2005
C. corn from 2007 to 2008
D. wheat from 2007 to 2008
GREEK AND LATIN DAY 1
Greek /Latin
Meaning
dynam-
power, energy, strength
-erg-
work
grav-
heavy, weighty
kilo-
thousand
kine-
motion
OBJECTIVE DAY 1
OBJECTIVE/LEARNING GOAL(S)
 1. I will know the difference between the
non-scientific and scientific definition of
work.
 2.
I will know the difference between
work and power.
 3.
I will be able to mathematically solve
story problems involving work and power.
☻We can easily say that the
nonscientific understanding for
work is like a job, or sitting and
working on your research paper.
☻In science, workis the
product of force and displacement.
☻What does the
word product mean?
☻Multiplication
☻Do you remember what
displacement means?
☻The difference between where you
start and stop.
☻Is there a force?
YES (There is a kick.)
☻Is there displacement?
YES (The crate starts and
stops at different points.)
☻Is work done? YES
(Work = Force x displacement)
FORCE AND DISPLACEMENT
MUST
BE IN THE SAME DIRECTION!
The weight lifter applies
a large force to hold the
barbell over his head. Is
the barbell moving?
NO
 IS THERE WORK BEING
DONE WHEN HE HOLDS
IT UP IN THE AIR?
NO
NO DISPLACEMENT –
NO WORK IS BEING
DONE!

SMALL GROUP
IS WORK BEING DONE?
EXPLAIN WHY FOR EACH
EXAMPLE.
B.
A.
C.
PARTNER PRACTICE –ANSWER
A.
Force
displacement
WORK IS BEING DONE!
FORCE and displacement
are in the SAME direction!
B.
Force
Force and
displacement are
perpendicular (900)
from each other.
displacement
WORK IS NOT BEING DONE!
FORCE and displacement
are in DIFFERENT directions!
C.
WORK IS NOT BEING DONE!
-- NO MOVEMENT
work= force x displacement
Equation: W = F x d
W=Fxd
What other equation
uses W?
W = mg
What
does W Weight!
mean?
What is the unit for force? newton
What is the unit for displacement?
meter
What is the unit for work then?
newton ∙ meter
N∙m
Science gives
NEWTON-METER
A SPECIAL NAME
JOULE!
The joule (J) is the SI unit
of work. A joule is equal to 1
newton-meter.

A weight lifter raises a 1600 newton barbell
to a height of 2.0 meters. How much work
was done?
Givens: 1600 newton = F
2.0 meters = d
Unknown: Work
Equation: W = Fd
Plug in numbers: W =1600 N × 2.0 m
Work = 3,200 N∙m
A karate expert kicks a crate with a force
of 2,250 N. The crate moves a
displacement of 5 m. How much work
was done?
W = 11,2500 N∙m
Givens: 2,250 N = F
5.0 m = d
Unknown: Work
Equation: W = Fd
Plug in numbers: W =2,2500 N × 5.0 m

How are work and
power related?
Power
is the
rate of doing
work.

Doing work at a
faster rate requires
more power.
Work is required to move snow
from one location to another.
One person uses a shovel and
another uses a snow blower.
Does one have more or less
power than the other? Explain.

 Because
the snow blower can remove more
snow in less time, it requires more power than
hand shoveling does.
Power = Work
time
P=W
t
What is the unit for Work?
Joule
What is the unit for time? second
What is the unit for power then?
Joule
s
Science gives
Joule/s
A SPECIAL NAME
The
WATT!
SI unit of power is the watt (W),
which is equal to one joule per
second.
You exert a
vertical force of
72 newtons to lift
a box to a height
of 1.0 meter in a
time of 2.0
seconds. How
much power is
used to lift the
box?
Givens: 72 newtons = F
1.0 meters = d
2 seconds = t
Unknown: Power
Equation: P = W/t
P = Fd/t
Plug in numbers:
P = (72 N)(1 m) ÷ 2 s
P = 36 W
Power = 36 J/s
Is your answer reasonable?
Explain
36 watts is not a lot of power, which
seems reasonable considering the
box was lifted slowly, through a
height of only 1 meter.
Your
family is moving to a new
apartment. While lifting a box
1.5 m straight up to put it on a
truck, you exert an upward
force of 200 N for 1.0 s. How
much power is required to do
this?
Givens: 200 newtons = F
1.5 meters = d
2 seconds = t
Unknown: Power
Equation: P = W/t
P = Fd/t
Plug in numbers:
P = (200 N)(1.5 m) ÷ 1 s
P = 300 W
Power = 300 J/s
FUN FACT:
The Watt is named after James Watt
(1736-1819).

Work is the product of force in the
direction of displacement.

SI Unit of work is joule or newton.meter.

Power is the rate of work.

SI Unit of power is watt or joule per
second.
1. A tractor exerts a force of
20,000 newtons to move a
trailer 8 meters. How much
work was done on the trailer?
a.
b.
c.
d.
2,500 J
4,000 J
20,000 J
160,000 J
2.
A tractor exerts a force of 20,000
newtons to move a trailer 8 meters.
How much work was done on the
trailer?
2,500 J
b. 4,000 J
c. 20,000 J
d. 160,000 J
a.
3.
A car exerts a force of
500 newtons to pull a boat
100 meters in 10 seconds. How
much power does the car use?
a.
b.
c.
d.
5000 W
6000 W
50 W
1000 W
3.
A car exerts a force of 500 newtons to
pull a boat 100 meters in 10 seconds.
How much power does the car use?
5000 W
b. 6000 W
c. 50 W
d. 1000 W
a.
In which of the following
cases is work being done
on an object?
a.
b.
c.
d.
pushing against a locked
door
suspending a heavy weight
with a strong chain
pulling a trailer up a hill
carrying a box down a
corridor
In which of the following cases is work being
done on an object?
A. pushing against a locked door
B. suspending a heavy weight with a strong chain
C. pulling a trailer up a hill
D. carrying a box down a corridor
C is the only answer
where Force and
displacement are in the
same direction!
Physical Science Text
Book
1. Students will read page 441 .
2. Students will answer questions # 1
-4
from the Reviewing Content
section
3. Students will complete Energy &
Power worksheet.
1.
A 10 newton force moves an object 2
meters in 1.5 seconds.
A. How much work was done?
B. How much power?
Agenda
 Quiz over work & power.
 Notes over kinetic energy and potential energy.
 Practice worksheet over kinetic energy, potential energy,
and work.

Givens: 10 N = F
2m=d
1.5 s = t
Unknowns = A) W
 Equations:
A) W = Fd

 Plug

in numbers:
A) W = Fd
= (10 N) (2 m)
B) P
B) P = W/t
W = 20 N∙m
 Do
20 J
you remember what N∙mequals?
Joule
 Plug

in numbers:
B) P = W/t
= (20 N∙m) ÷ (1.5s)
P = 13.33 N∙m÷ (s)
 Do
you remember what N∙m÷ (s)equals?
WATT
13.33 W
Q: THE CHART SHOWS HOW WATER IS USED
IN HOMES IN THE UNITED STATES. WHAT IS
MOST LIKELY TO SAVE THE MOST WATER?
A. take fewer baths
C. use only cold water in
washing machines
D. lower the amount of
water used for each
load in a dishwasher
Bath
2%
Leaks
14%
SC8.1.1.g DOK 2
B. use less water to flush
toilets
Other
2%
Clothes
washer
22%
Dishwasher
1%
Toilet
26%
Faucet
16%
Shower
17%
A: THE PERCENTAGES SHOW HOW WATER IS USED
IN HOMES IN THE UNITED STATES. WHAT IS MOST
LIKELY TO SAVE THE MOST WATER?
Bath
2%
SC8.1.1.g DOK 2
A. take fewer baths
Baths use very little water so this
would not conserve much
Other
water.
2%
B. use less water to flush toilets
Leaks
Toilets use the highest
14%
percentage of water so this
would be a good way to
conserve.
C. use only cold water in washing
Toilet
machines
Water temperature will not help 26%
with water conservation.
D. lower the amount of water used for
each load in a dishwasher
Dishwashers use the smallest
percentage of water so this
would not conserve much
water.
Clothes
washer
22%
Dishwasher
1%
Faucet
16%
Shower
17%
Q: CUBES
ARE PUT INTO TWO GROUPS,
ONES THAT CAN FLOAT AND ONES THAT
WILL SINK IN WATER.
WHAT
PROPERTY IS
BEING USED TO CLASSIFY THE CUBES?
A. density
B. mass
C. volume
D. weight
SC8.2.1.g DOK 1
A: CUBES ARE PUT INTO TWO GROUPS, ONES
THAT CAN FLOAT AND ONES THAT WILL SINK
IN WATER. WHAT PROPERTY IS BEING USED TO
CLASSIFY THE CUBES?
A. density
Density is how much mass is in a given volume. If the
cubes are denser than the water, they will sink. If
the cubes are less dense than the water, they will
float.
B. mass
Mass is how much matter is in a substance.
C. volume
Volume is how much space matter takes up.
D. weight
Weight is the pull of gravity on an object.
SC8.2.1.g DOK 1
Fiveworkerscan complete a
taskin 10 days. How long will it
take to complete the same work
if there are 10workers?
MATH BOOSTER DAY 2 -- ANSWER
HINT: MAKE A RATIO!
Answer: men
work
5
10 days
10
? = y days
5 × 10 = 10 × y
50 = 10y
50 ÷ 10 = y
5 days = y
Another Method,
Since 5 men can do a work in 10 days
Then 1 man can do the same work in 5 × 10 days = 50 days
{one man will take more time so multiply}
Therefore, 10 men can do the same work in 50 days ÷ 10 = 5
days { 10 men will take less time so divide}
GREEK AND LATIN DAY 2
Greek /Latin
Meaning
dynam-
power, energy,
strength
-erg-
work
grav-
heavy, weighty
kilo-
thousand
kine-
motion
Example
OBJECTIVES DAY 2
1.
I will know (knowledge): that
kinetic energy is energy of
motion.
2. I will know (knowledge): that
potential energy is energy of
position.
3. I will be able to (skill): apply the
concept of kinetic energy and
potential energy to a given
situation.
1. Work is a product of what two physical
quantities?
A. speed & force
B. force &
distance
C. power & force
D. motion and force
2. Which of the following is a unit of work?
A. Joule
B. Watt
C. Horsepower
D. Newton
3. How much work is doing when a 10 N force
moves an object 3.0 meters?
A. 0.3 joule
B. 3.0 joule
C. 3.3 joule
D. 30 joule


In an avalanche, a
mass of loose snow,
soil, or rock suddenly
gives way and slides
down the side of a
mountain. Describe
the amount of energy
released.
The avalanche
releases a great
amount of energy.
How are energy and work
related?

•
•
Energy is the ability to do work.
Work is the transfer of energy.
 Both
work and energy are
typically measured in joules (J).

Energy has different forms.
The sun gives off energy in the form of
heat and light.
 Plants convert sunlight into food.
 People convert food energy into
muscle movement.

 The
energy of motion is
calledkinetic energy.
Turn to a partner:
Kinetic energy depends
on what factors?
Answer: The kinetic energy
of any moving object
depends upon its mass and
speed.
SMALL GROUP:
WHAT ARE SOME EXAMPLES OF KINETIC
ENERGY?
Small group:
CAR
TRUCK
IF THEY HAVE THE SAME
VELOCITY, WHICH WOULD HAVE
MORE KE? DISCUSS WHY.
Small group:
ANSWER: THE TRUCK!
WHY?
Small group:

CAR
TRUCK
MORE MASS!
KINETIC ENERGY EQUATION
KE
m
=½
2
mv
= mass (kg)
v = velocity (m/s)
1.
What would happen to the
kinetic energy if you would
double the mass?
2. What would happen to the
kinetic energy if you would
double the speed?
KE = ½
2
mv
1.
KE = ½ mv2
KEm
double the mass
then you would
double your Kinetic Energy
They are a linear relationship!
1.
KE = ½ mv2
KEm
double the velocity
then you would
quadruple your kinetic energy
Modeled Practice
– Think Aloud
A 0.10 kilogram
bird is flying at a
constant speed of
8.0 m/s. What is
the bird’s kinetic
energy?
Read and Understand
What information are you given?
What unknown are you trying to
calculate?
The Kinetic Energy (KE)
of the bird.
Plan and Solve
What equation contains the given
quantities and the unknown?
Substitute the known values in the formula
for KE.
Science gives
2
2
kg ∙ m /s
A SPECIAL NAME
JOULE!
Turn to a partner:
Is your answer reasonable?
It seems reasonable, because
the bird has a low mass, so it
would not have much kinetic
energy.
1.
A 70 kilogram football player
is jogging at a speed of 2.0 m/s.
What is his kinetic energy?
A 70 kilogram football player is jogging at
a speed of 2.0 m/s. What is his kinetic energy?
Givens:
70 kg = m
2.0 m/s = v
Unknown:
KE
KE = 560 J
2
Equation:
KE = ½ mv
Plug in numbers:
KE = ½ (70 kg)(2.0 m/s)2
KE = ½ (70 kg)(4 m2/s2)
KE = 560 kg ∙ m2/s2
What is a kg ∙ m2/s2 ?
Joule
A 1400 kg car is moving at a speed of
25 m/s. Find the kinetic energy of the car.
Givens:
1400 kg =m
25 m/s = v
Unknown: KE
Equation:
KE = ½ mv2
Plug in numbers: = ½ (1400 kg)(25 m/s) 2
= ½ (1400 kg) (625 m2/s2)
KE =
437,500 J
Gravitational Potential Energy
An object’s
gravitational
potential energy
depends on its
mass, its height, and
the acceleration due
to gravity.
How would you define
gravitational potential energy?
Potential energy
is energy that is
stored as a result of
position or shape.
Explain the
physics behind
what happens
when a musician
pulls the string of
his cello to one
side, the string is
stretched and the
bow flies away.
The musician adds
energy to the cello
string by plucking
it. When the string is
stretched it gains
potential energy.
Then it is
transferred to the
bow and turns into
kinetic energy.

When an
object’s height
is raised to a
higher level,
the
gravitational
potential
energy
increases.


This diver has
gravitational
potential energy as
she stands at the end
of a diving board.
She gained the
potential energy by
doing work—
by climbing up the
steps to the diving
board.
 The
unit for mass ‘m’ is kilogram.
 The unit for height ‘h’ is meter.
 Acceleration due to gravity, g, has a
value in SI units of 9.8 m/s2 on Earth.
 The unit for gravitational potential
energy is joules.
Potential energy (PE)= mgh

Height is measured from
the ground or floor or
some other reference
level.
Small Group:
1. If you double the mass of an
object, what happens to the
PE?
2. If you double the height you
drop an object, what happens
to the PE?
1.
PE
= mgh
PEm
double the mass
then you would
double your Potential Energy
They are a linear relationship!
2. PE
= mgh
PEh
double the height
then you would
double your Potential Energy
They are a linear relationship!

What is the potential energy
relative to the water surface of a
diver at the top of a 10.0 meter high
diving platform? Suppose the diver
has a mass of 50.0 kilograms.
PE =mgh
Givens:
10.0 m = h
50.0 kg = m
What does g equal?
g = 9.8 m/s2
Unknown: PE
Equation: PE =mgh
Plug in numbers:
=(50.0 kg )(9.8 m/s2)(10.0 m)
=4,900
J
INDEPENDENT PRACTICE
1. What is the unit for kinetic energy?
2. What is the kinetic energy of a 30 kg
tiger chasing a deer at a rate of 4 m/s?
3. What is the unit for potential energy?
4. What is the potential energy of a 0.20 kg
apple falling from a tree branch at a
height of 5 meters?
INDEPENDENT PRACTICE
1. What is the unit for kinetic energy?
Answer: Joule
2. What is the kinetic energy of a 30 kg tiger
chasing a deer at a rate of 4 m/s?
Givens:
30 kg = m
4 m/s = v
Unknown: KE
Equation: KE = ½ mv2
Plug in numbers: = ½ mv2
= ½ (30 kg)(4 m/s)2
KE = 240 joules
INDEPENDENT PRACTICE
3. What are the units of potential energy?
Answer:
Joule
4. What is the potential energy of a 0.20 kg apple
falling from a tree branch at a height of 5
meters?
Givens:
0.20 kg = m
5m=h
g = 9.8 m/s2
Unknown: PE
Equation: PE = mgh
Plug in numbers: (0.20 kg)(9.8 m/s2)(5 m)
PE = 9.8 J
1. What is kinetic energy?
2. What is potential energy?
3. What is the unit for KE & PE?
1. What is kinetic energy?
the energy due to an object’s motion
2. What is potential energy?
the energy due to an object’s position
3. What is the unit for PE & KE?
joule
Physical Science Text Book
1. Students will read the following
topics on pages 464 and 468:
Solar energy
Geothermal Energy
Other Renewal Source
Conserving Energy Recourses
2. Students will complete Energy &
Power worksheet #2.
1. What is the SI unit of work and energy?
2. What is the work done by a worker
standing at a register for 5 hours?
3. What is the work done when a runner with
a mass of 80 kg runs a marathon in 5
hours?
Agenda:
Power Lab
1. What is the SI unit of work and energy?
Answer : joules.
2. What is the work done by a worker standing on a
register for 5 hours?
Answer: work done = zero , since there was no
motion or distance traveled.
3. What is the work done when a runner with a mass of
80 kg runs a marathon in 5 hours?
Answer: work done by gravity = zero, since
there was no motion or distance traveled in
the direction of the gravity.
Q: HOW ARE DENSITIES OBSERVED
AFTER POURING OIL AND WATER INTO
A CONTAINER?
A.
changes color
B.
mixes together
C.
creates an odor
D.
separates into layers
SC8.2.1.g DOK 2
A: HOW ARE DENSITIES OBSERVED AFTER
POURING OIL AND WATER INTO A CONTAINER?
A. changes color
Color does not affect density.
B. mixes together
The liquids will only mix together if they have
the same density
C. creates an odor
Smell does not affect density.
D. separate into layers
Denser liquids will settle to the bottom, while
less dense liquids will float at the top.
SC8.2.1.g DOK 2
Q: WHAT IS THIS A PICTURE OF?
A. community
B. ecosystem
C. food chain
D. food web
SC8.3.3.a DOK 1
A: WHAT IS THIS A PICTURE OF?
A. community
A community does not
show the flow of energy.
B. ecosystem
An ecosystem includes
abiotic and biotic factors
and does not show the
flow of energy.
C. food chain
A food chain follows a
single path of energy.
D. food web
A food web shows the
flow of energy among
plants and animals.
SC8.3.3.a DOK 1
MATH BOOSTER DAY 3
The Dress-Rite men’s clothing
store is having a sale. The price
of every sale item is of its
regular price. What percent of
the regular price must
you pay for a sale item?
MATH BOOSTER DAY 3 -- ANSWER
The Dress-Rite men’s clothing store is
having a sale. The price of every sale item
is of its regular price. What percent of
the regular price must you pay for a sale
item?
If the regular price of cloth is $100
Sale Price = × 100 = 80 %
GREEK & LATIN DAY 3
Greek /Latin
Meaning
dynam-
power, energy, strength
-erg-
work
grav-
heavy, weighty
kilo-
thousand
kine-
motion
Sentence
OBJECTIVE DAY 3
1. I will know how to set up the equipment to
effectively obtain data.
2. I will know how to take measurements for
the lab.
3. I will be able to apply the equation for work,
power and energy to calculate and solve for
the unknown variables involved in the
experiment.
1. STUDENTS WILL DISCUSS THE LAB WITH
THEIR LAB PARTNER.
2. STUDENTS WILL DO THE POWER LAB.
What was the relationship
between the time and the
power?
Physical Science Text Book
1. The students will copy & complete the
Comparing and Contrasting table on page
468.
2. Finish the Power Lab if you are not done.
1. Give an example in which one form of energy
changes to another form of energy.
2. Give an example in which PE changes to KE.
3. Give an example in which KE changes to PE.
4. What is the unit for energy?
Agenda
Notes over different forms of energy.
Discuss the Law of Conservation of Energy.
1. Give an example in which one form of energy
changes to another form of energy.
Answer: A light bulb, in which the electrical
energy changes to light energy or sound
energy or both.
2. Give an example in which potential energy
changes to kinetic energy.
Answer: A marker falling off a desk.
3. Give an example in which kinetic energy
changes to potential energy.
Answer: When you throw a ball up in the air.
4. What is the unit for energy?
Answer: joules
Q: WHY IS DENSITY USEFUL FOR
IDENTIFYING ELEMENTS?

Density predicts whether objects float.

Density varies at different temperatures.

Density is often unique to each element.

Different elements have the same densities.
SC8.2.1.g DOK 2
A: WHY IS DENSITY USEFUL FOR
IDENTIFYING ELEMENTS?
A. Density predicts whether objects float.
Objects of various densities will float, but do not
identify elements.
B. Density varies at different temperatures.
Density does not vary with temperature.
C. Density is often unique to each element.
Different elements tend to have different densities.
D. Different elements have the same densities.
Different elements tend to have different densities.
SC8.2.1.g DOK 2
Q: WHAT IS THE MOST DENSE SOLID
SHOWN ON THE TABLE?

mercury

pyrite

silver

zinc
SC8.2.1.g DOK 2
A: WHAT IS THE MOST DENSE SOLID
SHOWN ON THE TABLE?
A. mercury
13.55 g/cm3 is the most dense liquid, not solid.
B. pyrite
5.02 g/cm3 is not the most dense solid.
C. silver
10.50 g/cm3 is the most dense solid.
D. zinc
7.13 g/cm3 is not the most dense solid.
SC8.2.1.g DOK 2
MATH BOOSTER DAY 4
A shop owner increased the
selling price of a shirt from $20 to
$27. By what percentage was the
price increased?
MATH BOOSTER DAY 4 -- ANSWER
A shop owner increased the selling price of a shirt from
$20 to $27. By what percentage was the price increased?
Increase in the price = $27 - $20 = $7
Percentage increase in the price =
× 100
= (7 ÷ 20) × 100
= 35 %
GREEK AND LATIN DAY 4
Greek /Latin Picture
dynam-erggravkilokine-
OBJECTIVE DAY 4
1. I will know the different forms of
energy and the law of conservation
of energy.
2. I will be able to apply the law of
conservation of energy.
Energy classifications:
1. kinetic energy
2. potential energy
3. energy in fields such as those
produced by electromagnetic waves
Each of these forms of energy can be
converted into other forms of energy.

What are the major forms of energy?


What are the major forms of energy?
The major forms of energy are:
mechanical energy
thermal energy
chemical energy
electrical energy
electromagnetic energy
nuclear energy
Mechanical Energy
 The energy associated with the motion and
position of everyday objects is mechanical
energy.
 Mechanical energy is the sum of an object’s
potential energy and kinetic energy.
 What does sum mean?
 ADDITION
Thermal Energy
 The total potential energy and
kinetic energy of all the
microscopic particles in an object
make up its thermal energy.
 When an object’s atoms move
faster, its thermal energy
increases, and the object
becomes warmer.
This molten
metal is
extremely hot.
It contains a
great deal of
thermal energy.
Electrical Energy
 Electrical energy is the energy associated
with electric charges.
CHEMICAL ENERGY:
Chemical Energy:
The energy stored in
chemical bonds.
Electromagnetic Energy
 Electromagnetic energy is a form of
energy that travels through space in the form
of waves.
Visible light and X-rays are examples of
electromagnetic energy.
Nuclear Energy
The energy stored in
atomic nuclei is known as
nuclear energy.
Turn to a partner:
Discuss what fission and
fusion are.
Do you remember???????
•
•
Nuclear fission releases energy by
splitting nuclei apart.
Nuclear fusion releases energy
when less massive nuclei combine
to form a more massive nucleus.
The Law of Conservation of
Energy states that energy cannot
be created or destroyed, it can
only change form.
An example:
As you light a
match energy
is converted
from one form
to another.
The work done by friction changes kinetic
energy into thermal energy.

•
•
Friction within machinery reduces
efficiency. Friction is a major cause of
energy consumption in cars and factories.
In many cases, most of a falling object’s
potential energy is converted into thermal
energy because of air resistance.
 Explain
why speed skaters are slowed
down, even though they slide quickly
over smooth ice.
 They
are slowed down by friction with
the air and the surface of the ice.
The
gravitational potential
energy of an object is
converted to the kinetic
energy of motion as the
object falls.
• An
avalanche brings tons of snow
from the top of a mountain to the
valley floor.
• The elastic potential energy of a
compressed spring is converted
into kinetic energy as the spring
expands.

Some gulls use energy conversion to obtain
food by dropping oysters onto rocks. Kinetic
energy causes the shell to break on collision
with the rock.
Energy Conversion in Pendulums
A pendulum consists of a weight
swinging back and forth from a rope
or string.
AT THIS POINT THE
ENERGY OF POSITION
IS FULL, SO IT HAS PE!
WHILE IT IS MOVING IT HAS
KINETIC ENERGY, BUT IT ALSO
HAS ENERGY OF POSITION.
THERE IS NO LONGER ANY
PE BUT THERE IS KE!
FINALLY, THERE IS NO
MOVEMENT SO THERE IS
ONLY ENERGY OF POSITION.
THE TOTAL AMOUNT
OF ENERGY IS
CONSERVED!
Summary:
Energy Conversion in Pendulums
•
•
•
At the highest point in its
swing, the pendulum has
zero KE and maximum PE.
As the pendulum swings
downward, PE is converted
to KE.
At the bottom of the swing,
the pendulum has maximum
KE and zero PE.
Energy Conversion
and the Pole Vault
In the pole vault, an
athlete uses a
flexible pole to
propel it over a high
bar.
1. Some of the pole-vaulter’s kinetic
energy is converted into elastic
potential energy as the pole bends.
2. The pole springs back into shape,
propelling the pole-vaulter upward.
3. As the pole-vaulter rises, the kinetic energy
decreases while the gravitational potential
energy increases.
4. Once the highest point has been reached,
the gravitational potential energy begins to
convert back to kinetic energy.
Equation:
Mechanical energy =KE +PE
PE = 10 J
KE = ?
ME = ?
KE = 0 J
WHY?
GROUP PRACTICE
NO
MOVEMENT
ME = 10 J
½ WAY DOWN
KE = ? KE = 5 J
PE = ? PE = 5 J
ME = ?
ME = 10 J
NANOSECOND BEFORE IT
HITS THE GROUND
KE = ?
PE = ?
KE = 10 J
PE = 0
ME = ?
ME = 10 J
SMALL
GROUP:
Explain:
1. What you observed about
the mechanical energy (ME)
as the ball dropped.
2. What you observed
happened to KE and PE
as the ball dropped?
SMALL
GROUP
--
ANSWER
1. The Mechanical Energy
stayed the same at the top,
½ way down, and at the bottom.
(ME is the total energy!)
The ME was always 10 J.
2. The KE & PE switched places!
At the top:
KE = 0 PE = 10 J
At the bottom
KE = 10 J PE = 0
The PE was converted to KE as it fell!
Nonrenewable Energy Resources
Nonrenewable energy
resources exist in
limited quantities and,
once used, cannot be
replaced except over
the course of millions
of years.
Nonrenewable Energy Resources
Small Group: Discuss the major
nonrenewable sources of energy.
Nonrenewable energy resources include
oil, natural gas, coal, and uranium.
Fossil fuels
Oil, natural gas, and coal are known
as fossil fuels.
• They were formed
underground from the
remains of once-living
organisms.
• Fossil fuels account for
the great majority of the
world’s energy use.
• These fuels are not
distributed evenly
throughout the world.
Crude oil is
pumped out of
the ground,
refined, and
turned into
gasoline, fuel oil,
and other oil
products.
Renewable Energy Resources
Renewable energy
resources are resources
that can be replaced in a
relatively short period of
time.
Renewable Energy Resources
Small group: Discuss the major
renewable sources of energy.
Renewable energy resources include
hydroelectric, solar, geothermal, wind,
biomass, and, possibly in the future,
nuclear fusion.
1. A 2 kg heavy ball falls from a 3 m shelf. Just
before hitting the floor, what is its kinetic
energy?
 Answer : According to the Law of
Conservation of Energy, total energy at the top
will be equal to the total energy at the bottom.
 Total energy at top = Total energy at bottom
 PE = mgh

= (2 kg)(9.8 m/s2)(3 m)
PE = 58.8 J
(We know that the KE & PE are switched. )
Therefore,
KE = 58.8 J
1. Can you think of any example in which
you can create something out of nothing
or destroy something completely?
2. What types of energy are converted
when you use a cell phone?
1. Can you think of any example in which you can create
something out of nothing or destroy something
completely?
 Answer: We cannot create something out of
nothing or destroy something completely.
2. What types of energy are converted when you use a
cell phone?
 Answer : the electrical energy from the
battery changes sound energy & light energy.
Give examples of renewable and
nonrenewable resources.
Physical Science Text Book
1. Students will read pages 450 – 457
2. Students will answer the Review Questions
#1 – 10 on page 469.
3. Students will answer the Understanding Concepts
#11 – 22 on page 469.
BELL WORK & AGENDA DAY 5
TEACHER PREFERENCE
Q: WHY DOES A DROP OF VINEGAR
SPREAD OUT WHILE A DROP OF
VEGETABLE OIL BEADS UP?
A. Vegetable oil has a lower surface tension and lower
viscosity than vinegar.
B. Vinegar has a lower surface tension and lower
viscosity than vegetable oil.
C. Vegetable oil has a lower surface tension and higher
viscosity than vinegar.
D. Vinegar has a lower surface tension and higher
viscosity than vegetable oil.
SC8.2.1.g DOK 2
A: WHY DOES A DROP OF VINEGAR
SPREAD OUT WHILE A DROP OF
VEGETABLE OIL BEADS UP?
A. Vegetable oil has a lower surface tension and lower viscosity
than vinegar.
Vegetable oil has a higher surface tension and higher
viscosity than vinegar.
B. Vinegar has a lower surface tension and lower viscosity than
vegetable oil.
Surface tension is an attractive property of the surface of a
liquid and viscosity is a fluids resistance to flow. A lower
surface tension and viscosity allows the vinegar to flow
and spread out.
C. Vegetable oil has a lower surface tension and higher viscosity
than vinegar.
Vegetable oil has a higher surface tension and higher
viscosity than vinegar.
D. Vinegar has a lower surface tension and higher viscosity than
vegetable oil.
Vinegar has a lower surface tension and lower viscosity than
vegetable oil.
SC8.2.1.g DOK 2
Q: A LARGE
POPULATION OF FROGS IN A LAKE NEAR A CORNFIELD
HAD DECLINED OVER THE LAST FEW YEARS.
WHEN THE
SCIENTISTS RESEARCHED POSSIBLE EXPLANATIONS THEY CAME UP
WITH A FEW REASONS.
WHAT
IS A POSSIBLE EXPLANATION FOR
THE DECLINE IN THE FROG POPULATION?

tadpoles had not yet hatched

the scientists had an inaccurate count

neighborhood children were catching the frogs

pesticides were used to rid the area of insects
SC8.3.1.e
DOK1
A: A
LARGE POPULATION OF FROGS IN A LAKE NEAR A CORNFIELD
HAD DECLINED OVER THE LAST FEW YEARS.
WHEN THE
SCIENTISTS RESEARCHED POSSIBLE EXPLANATIONS THEY CAME UP
WITH A FEW REASONS.
WHAT
IS A POSSIBLE EXPLANATION FOR
THE DECLINE IN THE FROG POPULATION?
A. tadpoles had not yet hatched
This would not be a reason for a decline of a species.
B. the scientists had an inaccurate count
While this might be the case, most likely it is not.
C. neighborhood children were catching the frogs
This would not make a significant impact on the frog
population.
D. pesticides were used to rid the area of insects
The pesticides would deplete the insect population, leaving
little or no food for the frogs.
SC8.3.1.e
DOK1
MATH BOOSTER DAY 5

A car rental company offers two plans A and
B. In plan A, a customer pays a flat fee of $15
for the day plus 5 cents for each mile. In plan
B, a customer pays a flat fee of $12 for the
day plus 7 cents for each mile. If each
customer drives about 300 miles in a day
then which plan is better for the customer?
MATH BOOSTER DAY 5 -- ANSWER

A car rental company offers two plans A and B. In plan A, a
customer pays a flat fee of $15 for the day plus 5 cents for each
mile. In plan B, a customer pays a flat fee of $12 for the day
plus 7 cents for each mile. If each customer drives about 300
miles in a day then which plan is better for the customer?
Answer:
Cost with Plan A = $15 + 0.05 × 300 = 15 + 15 = $30
{to convert 5 cents into a dollar, divide by 100 = $0.05}
Cost with Plan B = $12 + 0.07 × 300 = 12 + 21 = $33
PLAN A IS CHEAPER!
GREEK AND LATIN DAY 5
USING COMPLETE SENTENCES WRITE A
PARAGRAPH THAT INCLUDES THE FOLLOWING
GREEK/LATIN ROOTS.
Greek /Latin paragraph
dynam
erg
grav
kilo
kine
OBJECTIVE DAY 5
 TEACHER
PREFERENCE
BELL WORK & AGENDA DAY 6
1. A 20 kg hammer is lifted 10 m. Calculate
the gravitational potential energy of the
hammer.
2. A 70 kg man is walking at a speed of 2 m/s.
What is his kinetic energy?
Agenda
Greek/Latin quiz
Compare & contrast forms of energy
BELL WORK DAY 6 – ANSWER #1
A 20 kg hammer is lifted 10 m. Calculate the
gravitational potential energy of the
hammer.
Givens: 20 kg =m
10 m = h
Know:
g = 9.8 m/s2
Unknown: PE
Equation: PE = mgh
Plug in numbers: (20 kg)(9.8 m/s2)(10 m)
Answer: = 1960 J
1.
BELL WORK DAY 6 – ANSWER #2
2. A 70 kg man is walking at a speed of 2 m/s.
What is his kinetic energy?
Givens: 70 kg =m
2 m/s = v
Unknown: KE
Equation: KE = ½ mv2
Plug in numbers: ½ (70 kg)(2 m/s)2
Answer: = 140 J
Q: HOW DO MOST WAVES TRANSFER
ENERGY?

through ocean waves

by a combination of waves

waves do not transfer energy

by the vibration of particles in a medium
SC8.2.3.a DOK 1
A: HOW DO MOST WAVES TRANSFER
ENERGY?
A. through ocean waves
Ocean waves are a type of wave.
B. by a combination of waves
Waves can be combined, but this does not explain
how they transfer energy.
C. waves do not transfer energy
Waves do transfer energy.
D. by the vibration of particles in a medium
When a particle vibrates, it passes its energy to a
particle next to it. The second particle will
vibrate like the first and in this way energy is
transferred through the medium.
SC8.2.3.a DOK 1
MAKE A LEAF BOB UP AND DOWN ON
THE WATER, BUT IT CANNOT MOVE THE
LEAF TOWARDS THE SHORE?

Waves only transfer crests.

Waves only transfer matter.

Waves only transfer energy.

Waves only transfer troughs.
SC8.2.3.a DOK 2
MAKE A LEAF BOB UP AND DOWN ON
THE WATER, BUT IT CANNOT MOVE THE
LEAF TOWARDS THE SHORE?
A. Waves only transfer crests.
Crests are the part of the wave at which the displacement of
the water from its normal level is highest.
B. Waves only transfer matter.
Waves only transfer energy, they do not move matter as they
travel.
C. Waves only transfer energy.
Waves only transfer energy, they do not move matter as they
travel. The leaf is pushed up by the crest of the wave, but
is not moved by the wave.
D. Waves only transfer troughs.
Troughs are the part of the wave at which the displacement
of the water from its normal level is lowest.
SC8.2.3.a DOK 2
MATH BOOSTER DAY 6
A studentworked for 6 hours and got paid $5 per hour.
Later, the student went shopping and bought two
magazines at $8.50 each and a pen at $7.25. How
much money does the student have left?
Total amount paid to Tom = 6 × $5 = $30
Cost of magazines = 2 × $8.50
= $17
Cost of pen = $7.25
Total expenditure = $17 + $7.25 = $24.25
Money left = $30 – $24.25 = $5.75
GREEK & LATIN DAY 6
Greek /Latin
Meaning
meter
measuring
axi
axis
goni
angle
leg
law
oper
work
OBJECTIVE DAY 6

I will know the similarity and difference
between kinetic and potential energy.
I
will be able to compare and contrast among
kinetic energy, potential energy and
mechanical energy.
SMALL GROUP -- ENERGY FOLDABLE
TURN TO A PARTNER -- DAY 6
PE
KE
Use the VEN diagram to compare and contrast
PE & KE.
TURN TO A PARTNER -- DAY 6 -ANSWER
PE
KE
PE & KE
energy of
position
unit
is a
Joule
PE & KE
are both
energy!
energy of
motion
1. Kinetic and Potential Energy both have
the same unit, which is a joule.
2. Potential energy is the energy due to
position.
3. Kinetic energy is the energy due to
motion.
4. Mechanical energy is KE & PE added
together.
EXIT QUESTION – DAY 6
Describe three
ways that you
used energy
resources today.
Students will complete the
concept map provided by
the teacher.
BELL
WORK
&
AGENDA DAY
7
Name the energy conversions
(energy trios) taking place in a
running car.
Hint: Energy trios have 3 kinds of energy
that are being changed.
Remember: dropping a ball has 2 -- PE goes
to KE.
Agenda
Make an Energy Poster showing the
conversion of energy trios along with the
descriptions.
BELL WORK DAY 7 -- ANSWER
Name the energy conversions taking place in a
running car.
Answer: Chemical energy from gas to
mechanical energy (engine) to
thermal energy (in the engine) or
sound energy.
Q: WHAT IS A DISTURBANCE THAT
TRANSFERS ENERGY THROUGH MATTER OR
EMPTY SPACE?

chemical change

heat

vibration

wave
SC8.2.3.a DOK 1
A: WHAT IS A DISTURBANCE THAT
TRANSFERS ENERGY THROUGH MATTER OR
EMPTY SPACE?
A. chemical change
Chemical changes happen when one or more
substances are changed into new substances.
B. heat
Is a form of energy that could be transferred.
C. vibration
Vibration is when particles move back and forth
quickly.
D. wave
A wave is any disturbance in a solid, liquid, gas, or
empty space.
SC8.2.3.a DOK 1
GRAMS) AND ENERGY (IN
CALORIES) PEOPLE OF
DIFFERENT AGES NEED EACH DAY. ABOUT HOW MUCH
PROTEIN WOULD A 75-YEAR-OLD FEMALE PROBABLY
NEED EACH DAY?
Age
Protein (grams)
Energy (calories)
Females
Males
Females
Males
7-10
34
34
2,400
2,400
11-12
46
45
2,200
2,700
15-16
46
56
2,100
2,800
19-22
44
56
2,100
2,900
23-50
44
56
2,000
2,700
51-70
44
56
1,800
2,300
A. 33 grams
B. 44 grams
C. 56 grams
D. 75 grams
SC8.1.1.g DOK 3
A: THE TABLE BELOW SHOWS HOW MUCH PROTEIN (IN GRAMS) AND ENERGY (IN
CALORIES) PEOPLE OF DIFFERENT AGES NEED EACH DAY. ABOUT HOW MUCH
PROTEIN WOULD A 75-YEAR-OLD FEMALE PROBABLY NEED EACH DAY?
Age
Protein (grams)
Energy (calories)
Females
Males
Females
Males
7-10
34
34
2,400
2,400
11-12
46
45
2,200
2,700
15-16
46
56
2,100
2,800
19-22
44
56
2,100
2,900
23-50
44
56
2,000
2,700
51-70
44
56
1,800
2,300
A. 33 grams
As females get older, they are in need of more protein. A female between the ages
of 51-70 needs 44 grams, so a 75 year old female would need the same or more.
B. 44 grams
44 grams seems to keep with the pattern of protein needed for females.
C. 56 grams
As females get older, they are in need of more protein. However, the table shows a
steady increase. This would show a steep increase in protein.
D. 75 grams
As females get older, they are in need of more protein. However, the table shows a
steady increase. This would show a steep increase in protein.
SC8.1.1.g DOK 3
MATH BOOSTER DAY 7
One family uses an electric
water heater. What is their
cost per year for machine A
and for machine D?
MATH BOOSTER DAY 7 -- ANSWER
One family uses an electric water heater. What is their cost
per year for machine A and for machine D?
Answer:
Machine A $10
Machine D $60
GREEK & LATIN DAY 7
Greek /Latin Meaning
meter
measuring
axi
axis
goni
angle
leg
law
oper
work
Example
OBJECTIVE DAY 7
I
will know the steps it takes
for one form of energy to
change into another form of
energy.
 I will be able to identify and
draw picture examples of
energy trios.
 I will be able to describe the
examples of energy trios.
INDEPENDENT WORK DAY 7

What is the gravitational potential energy
of a 61.2 kg person standing on the roof
of a 10-story building relative to
(a) the tenth floor,
 (b) the sixth floor,
 (c) the first floor?

(Each story is 2.50 m high.)
 Group poster presentations.
A pendulum weight is released in
position A. The weight moves
through positions B, C, D, and E.
Q 1. At what location (s) does the
pendulum have minimum
potential energy?
Q 2. At what location (s) does the
pendulum have maximum
kinetic energy?
Q 3. If the mass of the pendulum is
0.05 kg and has a speed of 2
m/s at the location C, find its
kinetic energy.
Q 4. What is the pendulum’s
potential energy at A?
BELL WORK & AGENDA DAY 8
1. What is the Law of
Conservation of Energy?
2. Give an example in which one
form of energy gets converted
into another form.
3. What is the SI unit of energy?
Agenda – To Verify the Law of
Conservation of Energy Lab
BELL WORK DAY 8 -- ANSWERS
1. What is the Law of Conservation of Energy?
Answer: Energy cannot be created nor
destroyed but can only change form.
2. Give an example in which one form of energy gets
converted into another form.
Answer: A light bulb – A light bulb converts the
electrical energy to light and heat energy.
3. What is the SI unit of energy?
Answer: joules
Q: WHAT IS AN
POPULATION?
EXAMPLE OF A

all of the fish in a pond

all of the insects in a swamp

all of the amphibians in a rain forest

all of the blue gill in Lake Cunningham
SC8.3.3.e
DOK1
A: WHAT IS AN
POPULATION?
EXAMPLE OF A
A. all of the fish in a pond
This is not specific enough for the definition of population.
B. all of the insects in a swamp
This is not specific enough for the definition of population.
C. all of the amphibians in a rain forest
This is not specific enough for the definition of population.
D. all of the blue gill in Lake Cunningham
A population is all of a specific species living in a certain
place.
SC8.3.3.e
DOK1
Q: WHICH OF THESE WAVES REQUIRE A
MEDIUM?

light

microwaves

radio

sound
SC8.2.3.a DOK 1
A: WHICH OF THESE WAVES REQUIRE A
MEDIUM?
A. light
Light waves are an electromagnetic wave which
does not require a medium.
B. microwaves
Microwaves are an electromagnetic wave which
does not require a medium.
C. radio
Radio waves are an electromagnetic wave which
does not require a medium.
D. sound
Sound waves require a medium to travel through.
SC8.2.3.a DOK 1
MATH BOOSTER DAY 8
Cost
Year
$3.40
2007
$2.90
2008
$1.40
2009
$4.10
2010
$3.90
2011
Calculate the average price
of gas from 2007 to 2011.
MATH BOOSTER DAY 8 --ANSWER
Cost
Year
$3.40
2007
$2.90
2008
$1.40
2009
$4.10
2010
$3.90
2011
$3.40 + $2.90 + $1.40 + $4.10 +
$3.90 = $15.70
$15.70 ÷ 5 = $3.14
GREEK & LATIN DAY 8
Greek /Latin Meaning
meter
measuring
axi
axis
goni
angle
leg
law
oper
work
Sentence
OBJECTIVES DAY 8


I will know that the Law of
Conservation of Energy is true
for any given situation and it can
be verified.
I will conduct an experiment to
verify the Law of Conservation of
Energy .
ENERGY LAB
INDEPENDENT WORK DAY 8
Once
the group is
finished with the data
collection, each person
will work separately on
the calculations part.
Write a brief conclusion of
what you found in your lab.
1.
Answer the following questions:
a. When you heat a pot of water over a
flame, what form of energy is
occurring when the water is
boiling?
b. Can an object have both kinetic
energy and potential energy at the
same time? Explain.
2. Complete energy lab.
BELL WORK & AGENDA DAY 9
1. How do energy conversions take place in
roller coasters?
2. A 0.15 kg ball is thrown into the air and rises
to a height of 20 m. How much kinetic
energy did the ball initially have?
 Agenda
Review for the test
BELL WORK DAY 9 -- ANSWERS
1. How do energy conversions take place in roller
coasters?
Answer: When the roller coaster is at a certain
height it has potential energy and when its rolls
down, the potential energy changes to kinetic
energy. The total (Mechanical Energy) remains
the same.
2. A 0.15 kg ball is thrown into the air and rises to a
height of 20 m. How much kinetic energy did the
ball initially have?
Answer: All the kinetic energy got converted into
gravitational potential energy.
Givens: 0.15 kg 20 m = h
know g = 9.8 m/s2
Unknown: KE
Equation: KE = PE
= mgh
Plug in numbers:
= (0.15 kg)(9.8 m/s2)(20 m)
Answer:
= 29.4 joules
DAYS IT TOOK A SEED TO SPROUT AT THREE
DIFFERENT TEMPERATURES.
BASED ON THE
CHART, HOW LONG WILL IT TAKE FOR THE
SAME KIND OF SEED TO SPROUT AT


75°F?
11 days
less than 11 days
Temperature
Days Needed to
Sprout
60° F
15
65° F
13
70° F
11

more than 11 days

the number of days cannot be predicted
SC8.1.1.g DOK 3
DAYS IT TOOK A SEED TO SPROUT AT THREE
DIFFERENT TEMPERATURES.
BASED ON THE
CHART, HOW LONG WILL IT TAKE FOR THE
SAME KIND OF SEED TO SPROUT AT
75°F?
A. 11 days
As temperature increases, the days needed to sprout
decreases so at 75°F the plant would sprout in less than 11 days.
B. less than 11 days
Temperat
Days
As temperature increases, the days needed to
ure
Needed to
sprout decreases so at 75°F the plant would
Sprout
sprout in less than 11 days.
60° F
15
C. more than 11 days
As temperature increases, the days needed
65° F
13
to sprout decreases so at 75°F the plant
70° F
11
would sprout in less than 11 days.
D. the number of days cannot be predicted
As temperature increases, the days needed to sprout
decreases so at 75°F the plant would sprout in less than 11 days.
SC8.1.1.g DOK 3
CAN BE OBSERVED AS LIGHT WAVES
PASS FROM ONE MEDIUM TO ANOTHER
AND CHANGE SPEED?

diffraction

reflection

refraction

separation
SC8.2.3.b DOK 1
CAN BE OBSERVED AS LIGHT WAVES
PASS FROM ONE MEDIUM TO ANOTHER
AND CHANGE SPEED?
A. diffraction
Diffraction is the bending of waves around barriers or
through openings.
B. reflection
Reflection happens when light bounces off an object.
C. refraction
Refraction is the bending of a wave as it passes at an
angle from one substance, or material, to another.
D. separation
White light can be separated into different colors
during refraction.
SC8.2.3.b DOK 1
MATH BOOSTER DAY 9
Solve for y.
MATH BOOSTER DAY 9
Solve for y
Answer:
Do cross multiplication
y × 8 = 10 × 4
y8 = 40
y = 40 ÷ 8
y= 5
GREEK & LATIN DAY 9
Greek /Latin
meter
axi
goni
leg
oper
Picture
OBJECTIVE DAY 9
I will know the definitions and
concepts of work, power, and
energy.
I will be able to mathematically
solve story problems involving
work, power, and energy.
1.
How are work and energy related?
Energy is the rate of doing work.
b. Work is a form of energy.
c. Work is the transfer of energy.
d. Energy is created by work.
a.
ANS:
C
Work is the transfer of energy.
2.
A moving object with a mass of 10 kg has
320 J of kinetic energy due to its motion.
How fast is the object moving?
8 m/s
b) 10 m/s
c) 32 m/s
d) 64 m/s
a)
2.
A moving object with a mass of 10 kg has 320 J of kinetic
energy due to its motion. How fast is the object moving?
a)
8 m/s
b)
10 m/s
c)
32 m/s
d)
64 m/s
Givens: 10 kg = m
320 J = KE
Unknown: v
Equation: KE = ½ mv2
Plug in numbers: 320 J = ½ (10 kg)(v2)
Answer: 8 m/s (A)
3.
Which of these is an example of elastic
potential energy?
a bow prepared to release an arrow
b. a rubber ball thrown into the air
c. a book about to fall from a table
d. a truck pulling a trailer
a.
ANS:
A
4.
A small airplane and a helicopter have
identical masses. If the airplane’s altitude
compared to the ground is three times
that of the helicopter, how much more
gravitational potential energy does the
airplane have than the helicopter?
a) 0.333 times as much
b) 3 times as much
c) 6 times as much
d) 9 times as much
ANS: B – linear relationship
5.
The energy stored in the bonds between
atoms of a compound is what kind of
energy?
a) atomic
b) chemical
c) electromagnetic
d) thermal
ANS: B
6.
You lift a book from the floor to a bookshelf 1.0 m above the ground.
How much power is used if the upward force is 15.0 N and you do the
work in 2.0 s?
Givens:
1.0 m = d
15.0 N = F
2.0 s = t
Know: g = 9.8 m/s2
Unknown: P
Equations: W = Fd
P=W÷t
P = Fd ÷ t
Plug in numbers: P = (15 N)(1.0 m) ÷ (2.0 s)
Answer: =
7.5 W
INDEPENDENT
WORK
DAY 9
Students will do the review worksheet.
1. Give an example in which the potential
energy changes to kinetic energy and
vice versa.
2. Describe how energy can be converted
from one form to another in a wind-up
toy.
3. Describe the energy of a playground
swing at its highest position.
Finish the review sheet.
BELL WORK & AGENDA DAY 10

1. What is the formula to calculate kinetic
energy?

2. How does one form of energy get converted
into another form in a cell phone device?


3. A 0.50 kg ball is thrown into the air and rises
to a height of 15 m. How much potential and
kinetic energy did the ball initially have?
Agenda
Test over work, power, kinetic & potential
energy, and law of conservation of
energy
BELL WORK DAY 10 – ANSWERS #1 & #2
 1.
What is the formula to calculate kinetic
energy?
Answer: Kinetic Energy = ½ mv2
 2. How does the one form of energy get
converted into another form in a cell phone
device?
Answer: The chemical energy of the
battery changes into electrical
energy, which turns the cell phone on.
When we talk on the phone the sound
energy gets converted into electrical
energy, which is transmitted through
the air.
BELL WORK DAY 10 – ANSWER #3

3. A 0.50 kg ball is thrown into the air and rises to a height of 15 m.
How much potential and kinetic energy did the ball initially have?
Answer: Since the ball’s initial stage is at ground
level the potential energy of the ball will be zero.
All the kinetic energy got converted into
gravitational potential energy.
Givens: 0.5 kg = m
15 m = h g = 9.8 m/s2
Unknown: KE & PE
Equation: KE = PE = mgh
Plug in numbers: = (0.5 kg)(9.8 m/s2)(15 m)
= 73.5 joules
Answer:
KE = 73.5 J
PE = 0 J
Q: WHAT PROPERTY OF MATTER CAUSES
WAVES TO TRAVEL AT DIFFERENT SPEEDS
THROUGH SOLIDS, LIQUIDS, AND GASES?
A. density
B. color
C. mass
D. size
SC8.2.3.b DOK 1
A: WHAT PROPERTY OF MATTER CAUSES
WAVES TO TRAVEL AT DIFFERENT SPEEDS
THROUGH SOLIDS, LIQUIDS, AND GASES?
A. density
The less dense that matter is, the farther away the
particles are, and the slower the wave will travel
through it.
B. color
The color of a material has nothing to do with how
fast a wave will travel.
C. mass
The mass of a material has nothing to do with how
fast a wave will travel.
D. size
The size of a material has nothing to do with how
fast a wave will travel
SC8.2.3.b DOK 1
Q: WHICH HUMAN BODY SYSTEM
CONTROLS ALL BODY FUNCTIONS?
A.
B.
C.
D.
circulatory system
digestive system
nervous system
urinary system
S.C.8.3.1.d DOK1
A: WHICH HUMAN BODY SYSTEM
CONTROLS ALL BODY FUNCTIONS?
circulatory system
The circulatory system contains blood, which carries
nutrients and oxygen to all body parts.
B. digestive system
The digestive system breaks down the food in the body
and uses it for energy.
C. nervous system
The nervous system controls all human body
functions by transferring information to and from
the brain.
D. urinary system
The urinary system cleans and removes waste
from the blood.
A.
S.C.8.3.1.d DOK1
MATH BOOSTER DAY 10

If a = - 3 and b = 3, what is the value of
MATH BOOSTER DAY 10 -- ANSWER

=
If a = - 3 and b = 3, what is the value of
=
= -14
GREEK & LATIN DAY 10
Greek /Latin
meter
axi
goni
leg
oper
Paragraph
OBJECTIVE
DAY 10
1. I will know the definitions
and concepts of work,
power, and energy.
2. I will be able to
mathematically solve story
problems for work, power,
and energy.
INDEPENDENT WORK DAY 10
TEST
EXIT QUESTION:
Is there
anything you
could have
done differently
in the energy
unit?
1. Read pages # 474 to 475 and answer the
question given below.
Which has more thermal energy, a
cup of tea or a pitcher of juice?