Physical Science Syllabus
Instructor
Kevin Molohon
E-mail: Kevin.Molohon@anoka.k12.mn.us
Phone: 763-506-7084
Office Hours: 6:30 -7:00 am on any Monday that school is in session. Please
schedule appointments for any other day/time. Where: Room A207
Text
Science Spectrum: Physical Science (Holt)
Course Description
Physical science is an introductory, two trimester science course with chemistry,
physics and earth science concepts embedded throughout the course. The course
is designed to be lab-based, which means learning results from student activities.
PARTICIPATION is a MUST!!! This course is also intended to provide students a
more structured and systematic method of viewing the world and the information
around them.
Required Materials
Bring the following items to class every day:
- a pen or pencil (preferably both)
- loose leaf paper
- a calculator (this is especially useful during Physical Science A)
- a 3-ring binder (1.5 - 2 inch) for your daily work. You will need this every
day for class. (I have plenty of binders that I am willing to share with
you.)
Topics
Physical Science A
-
The Nature of Science
Physics
Geology
Physical Science B
-
Matter
The Periodic Table
Energy
The Universe
What can you expect from me?
-
I will always do my best to help you to learn the material.
I will enjoy having you in my class.
I will never lecture to you for the entire class period.
I will do my best to be fair to everyone, but I will also try to do what is
right in each circumstance.
I will bring unbridled enthusiasm to class.
Classroom Expectations (a.k.a. “What I Expect From You”)
-
-
-
-
Treat each other, the teacher and everything in the room with respect.
Be on time and be prepared for class. If an assignment is due, have it
ready to turn in. If your pencil needs sharpening, do it right away. I want
to make the most of our time together.
Participate! Participate! Participate! This is the biggest key to how well
you do in this class (and in life). I expect you to give your full attention to
what we are doing in class (this means I won’t allow you to work on
assignments for other classes during our class).
Be safe in the lab. If you can’t be safe in the lab area, you can’t do the
labs and that makes it very hard to pass a lab course. Any removals from
lab, or class, mean zero points for the day.
Be organized. Keep your supplies, notebook, homework, etc. in good shape.
Grading Policy
A
AB+
F
93-100%
90-92%
87-89%
Below 60%
B
BC+
83-86%
80-82%
77-79%
C
CD
73-76%
70-72%
60-69%
Grading is broken down as follows: tests (60%) and quizzes (15%), lab work,
homework and class participation (15%) and the District Final (10%). Please note
that I use weighted grades. This means that I have the percentages for each
type of assignment entered into my grade program and the grade is calculated
automatically based on them. Grades will be updated at least every two weeks.
The Three-Ring Binder
Every student needs a three-ring binder for class. This is the most
important thing for you if you want to do well in class. EVERYTHING
that we do in class gets put into the three-ring binder. Here’s how you make
the most out of your three-ring binder (and this class, too):
• Bring your binder to class every day.
• Put your new daily work in your binder right after the previous day’s
work.
• Take your binder home and finish any work that you don’t get done in
class.
• Read through your binder (from the beginning of the unit up to where
we left off that day) at least two times a week.
• I post the answers to the lessons that we do in class on my web site.
Correct your work and ask me questions about things that you don’t
understand.
Re-tests
I allow students to re-take tests in order to earn a better grade. Students who
don’t pass a test MUST re-take it. Here are the rules:
• All re-takes are taken before school, at 7am, in the classroom (unless you
make special arrangements with me.).
• All work for the unit must be complete, corrected and in order in the threering binder, BEFORE a student can re-test.
• Students may come in early (7am) for review sessions with me in the days
before they re-test.
• I like all re-takes to be taken within a week of the original test.
Extra Credit
•
Extra credit opportunities will be made available to students throughout the
trimester. Students can also earn extra credit by doing exceptional work on
class assignments.
Late or Missing Assignments
Assignments are due at the beginning of class on their assigned due date
It is the student’s responsibility to obtain the assignments he or she has
missed for an excused absence. Ask a classmate, or the teacher, about what
you missed. The class web page will have the assignments posted daily.
• Late assignments will be accepted up to one week past the due date, but will
only receive half credit.
•
•
Tardy Policy
•
•
Timeliness is expected and excess tardiness will earn consequences.
Tardies will be reported to the student’s house office and may earn
detention.
Leaving the classroom
•
I only have you in class for 67 minutes a day and I want to make the most of
the time that we have together. Students may leave the room to use the
restroom (I don’t want you to plan on a daily bathroom break, but I don’t
want to limit your access to it either – be responsible!). Students need to
make the most of their 7 minute passing time between classes.
Electronics
There will be no cell phone, I-Pod, MP3 player or other electronics use allowed in
class. Please don’t have them out/in sight during class. The only exceptions to this
rule are that I will sometimes let you use the calculator on your cell phone (not on
tests, though) and I am willing to let you use your own internet-ready device during
lessons which involve the use of the Internet.
Homework for Parents/Guardians:
I need you to register your student for my class. You do this by going to my web
page and clicking on the “Student Registration” selection on the left side of
the page. Enter the requested information. I will make a distribution list of all of
my families and use it to send out class news and updates. Please do this by
Friday, September 5th. Here is the address for my web page:
http://anokahennepin.schoolwires.net/Page/14653
SPECIAL NOTE: Please make sure to do your homework. It is worth 5 points
to your child (and so much more than that to me). Thanks!
Homework for Everyone
(also known as “Quality Family Time”):
While you are at my page, look around and get yourself familiar with it. Access the
textbook on-line to make sure that it works for you. Check out the links for the
STEM Fair page and for the LibGuide for the Honors Project. You will also notice
the calendar for the course. On the left side of the page you will see links to my
homepage (where you will useful tools and information) and the link to the first
unit that we will be doing – The Nature of Science. Click on this link to see the
resources for the unit. When we do more units I will open up the links to them.
Special Homework Assignment for ALL Students:
I want to be able to send my students reminders about special events,
test, etc. in class. I need you to follow the instructions for signing up
for Remind (a really cool web-based text messaging tool). I have
attached the instruction sheet at the end of this packet.
Honors Physical Science
If you are in Honors Physical Science, there are a few more things that you need
to know. First of all the grading scale is different for Honors Physical Science.
Here is the breakdown:
Item
Percentage of Final Grade
Tests
50
Quizzes/Lab Work/ Participation
15
Honors Project
25
District Final Exam
10
What is the Honors Project?
The Honors Project is what makes this class an Honors class. You are probably the
most familiar with this as a Science Fair Project. You will research an area of
science that interests you, generate a question within that area, design and run an
experiment to answer the question and then share your findings at the District
Science Fair and/or the Regional Science Fair. The Honors Project is science at its
highest, most authentic level. You will develop research, critical thinking and
problem-solving skills that you never realized you had.
Do I need anything special for the Honors Project?
Yes. Here is what you will need to start things off:
1. A separate three-ring binder (a 2” one should be fine) for you Honor’s
Project work. Please keep this at home.
2. Please make careful note of the dates for the various Science Fairs. You will
need to present your project at the District and/or the Regional Science
Fair. The Fair dates are listed below – please reserve at least one of these
dates now. NOTE: Only the Regional Science Fair can send projects on
to the State Science Fair.
Fair
District STEM Fair
Regional Science Fair
Date
February 7th
February 21st
State Science Fair
March 21st- 24th
Location
Coon Rapids High School
St. Cloud State University
Doubletree by Hilton
(in Bloomington)
Science Spectrum Answer Key continued
Review
3. Possible answers: magnifying glass, human
eye, microscope
1. In electrical conductors, electrons can
move freely throughout the substance.
Therefore, electrical conductors can
transfer electric charge easily. In electrical
insulators, electrons cannot move freely.
Therefore, electrical insulators do not
transfer electric charge easily.
2. There is more friction between your feet
and a carpeted floor than between your
feet and a smooth floor. The greater friction
causes more electrons to move between the
floor and your body.
3. More electrons will move into student A’s body
than into student B’s body. Therefore, the
difference in electric charge between student
A and the doorknob will be greater. Student A
is more likely to receive an electric shock.
4. The greater the charges, the greater the
electric force.
5. toward the object
4. Rainbows form because of a combination
of dispersion and reflection. Dispersion
happens because different wavelengths of
light travel at different speeds in a medium.
If all wavelengths of light traveled at the
same speed in a given medium, no dispersion
would occur, and rainbows would not form.
5. converging
6. green light
Chapter 17 Electricity
SECTION 1 ELECTRIC CHARGE AND
FORCE
1. The particle has a positive charge.
2. electrons
3. They have opposite electric charges.
4. negative
5. 1.6 10 19 C
6. Electrons are located in the outer parts of
an atom.
7. The toaster would not work if the cord were
made entirely of plastic. Plastic is an insulator,
so electricity does not flow through it easily.
8. It contains the same number of protons as
electrons.
9. It has a negative charge, so it must have
more electrons than protons.
10. friction
11. Electrons cannot move easily through an
insulator.
12. positive
13. a force a charged object experiences due to
interactions with other charged objects
14. amount of charge on each object and distance between the objects
15. away from each other
16. a force that can affect objects that are not
touching
17. because a positively charged object will
repel another positively charged object
18. Electric field lines show how a positively
charged particle would move. A positively
charged particle would be repelled by
the positively charged particles in the left
image.
SECTION 2 CURRENT
1. energy that charged objects have that
depends on their position in an electric field
2. It decreases.
3. It would decrease.
4. voltage
5. 12 V
6. from areas of high potential to areas of low
potential
7. electrons
8. from right to left
9. the slowing of the movement of charged
particles through a substance
10. resistance
11. They travel through the wires in the bulb.
12. by dividing voltage by current
13. V฀ ฀IR;
V฀ ฀(0.50 A) × (12 ); V฀ ฀6 V
14. Electrons can move through them easily.
15. Metal is a better electrical conductor than
plastic, so the metal fork probably has
lower resistance than the plastic fork.
16. to allow electricity to flow through the device
17. a material that has no resistance below a
certain temperature
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Interactive Reader
27
Answer Key
Science Spectrum Answer Key continued
Review
18. The current keeps flowing.
19. less friction
1. In a closed circuit, current can flow in a
closed loop. In an open circuit, current
cannot flow.
2. Student should label the vertical lines
“Battery,” the circled zigzag lines “Light
bulb,” the uncircled zigzag lines “Resistor,”
and the pair of small circles “Switch.”
3. in series
4. The switch in the circuit is open. Therefore,
the circuit is open, and no current flows in
it. The light bulb will not light up.
5. Both fuses and circuit breakers help to
prevent circuits from becoming overloaded.
The main difference between a fuse and
a circuit breaker is that a fuse has to be
replaced if a circuit overloads, but a circuit
breaker does not.
Review
1. Possible answer: Current is equal to voltage
divided by resistance.
2. top row: conductor; low resistance
second row: insulator; high resistance
third row: high resistance
fourth row: conductor
bottom row: insulator
3. R V฀ ฀I;
R (24 V)฀ ฀(0.80 A); R 30
4. I V฀ ฀R;
I (1.5 V) (3.5 ); I 0.43 A
SECTION 3 CIRCUITS
1. a complete loop around which electrons can
flow
2. The light bulb is lit, so current must be
flowing.
3. to easily describe how different parts of a
circuit are connected
4. a device used to control the amount of
current flowing through a circuit
5. a resistor
6. Student should circle the longer line.
7. The voltage is divided among the different
components, so each component must have
less voltage than the battery.
8. current
9. Student should circle the two vertical lines.
10. 100 W
11. It increases.
12. P฀ ฀IV;
P฀ ฀(9.1 A) (120 V);
P฀ ฀1,100 W or 1.1 kW
13. 1 J/s and 1 V•A
14. a circuit in which the wires carry more
current than is safe
15. If the fuse is connected in parallel with
the rest of the devices, current will still
flow through the circuit if the fuse blows.
Therefore, the fuse cannot protect the
devices in the circuit.
Chapter 18 Magnetism
SECTION 1 MAGNETS AND MAGNETIC
FIELDS
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
a naturally magnetic rock
points with opposite magnetic properties
a substance that is always magnetic
magnet A
They are less magnetic than nails closer to
the magnet.
The freely moving magnet would move
toward the magnet being held.
Possible answers: curved, circular, or oval
The magnetic fields of individual atoms
cancel each other out.
Possible answers: away from the north pole,
toward the south pole
south
south
straight down
Review
1. Student should label the top of the magnet
“N” and the bottom of the magnet “S.”
2. The magnets of pair B will move together
because their north and south poles are
near each other.
3. Moving electric charges produce magnetic
fields.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Interactive Reader
28
Answer Key
INTERMEDIATE/SECONDARY ARTICLE:
Measuring Electricity
We use electricity for hundreds of tasks every day. It makes our lives productive and enjoyable, yet it remains a
mysterious force to most of us. Understanding electricity and how it is measured is confusing because we cannot
see it. We are familiar with terms such as watt, volt, and amp, but most of us do not have a clear understanding of
these terms. We buy a 60-watt lightbulb, a tool that requires 120 volts, or a vacuum cleaner that uses 8.8 amps, and
don’t really think about what those measurements mean. We are confident that when we plug them in, they will work.
It is important to understand electricity, because we rely on it for so many things. Electricity is the flow of electrons.
Using the flow of water as an analogy can make concepts of electricity easier to understand. The flow of electrons in
a circuit is similar to water running through a hose.
If you could look into a hose at a given point, you would see that a certain amount of water passes that point each
second. The amount of water depends on how much pressure is being applied––how hard the water is being pushed.
It also depends on the diameter of the hose. The more forceful the pressure and the larger the diameter of the hose,
the more water passes each second. The flow of electrons through a wire depends on the electrical pressure
pushing the electrons and on the cross-sectional area of the wire.
Voltage
The pressure that pushes electrons in an electrical circuit is called voltage. Using the water analogy, if a tank of water were suspended one
meter above the ground with a one-centimeter pipe coming out of the
bottom, the water pressure would be similar to the force of a shower. If
the same water tank were suspended 10 meters above the ground, the
force of the water would be much greater, possibly enough to hurt you. (If
you jumped from a one-meter diving board, the force when you hit the
water would not be too great. If you jumped from a 10-meter board, the
force would be much greater.)
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Voltage (V) is a measure of pressure, or electromotive force, applied to electrons to make them move.
It is a measure of the strength of the electric current in a circuit. Voltage is measured in volts (V). A
volt is the amount of electromotive force (emf) needed to push a current of one ampere through a
resistance of one ohm. This definition will make more sense after you learn about current and resistance.
P
Just as the 10-meter tank applies greater pressure than the 1-meter tank, a 10-volt power supply
(such as a battery) would apply greater electromotive force than a 1-volt power supply. Voltage potential is the electrical term that is analogous to water pressure.
AA batteries are 1.5-volt; they apply a small amount of voltage or pressure for lighting small flashlight bulbs. A car usually has a 12-volt battery––it applies more voltage to push current through
circuits to operate the radio or defroster. The standard voltage of wall outlets is 120 volts––a potentially dangerous amount of voltage. An electric clothes dryer is usually wired at 240 volts––a very
dangerous amount of voltage.
Current
The flow of electrons can be compared to the flow of molecules of water.
The water current is the number of molecules flowing past a fixed point;
electrical current is the number of electrons flowing past a fixed point.
Electrical current is defined as electrons flowing between two points
having a difference in voltage potential. Current is measured in amperes
or amps (A). One ampere is 6.25 x 1018 electrons per second passing
through a circuit.
With water, as the diameter of the pipe increases, so does the amount of
water that can flow through it. With electricity, a conducting wire is the
pipe. As the cross-sectional area of the wire increases, so does the
amount of electric current (number of electrons) that can flow through it.
Energy Exchange – Mar/Apr 2003
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PO Box 10101
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SLSH
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SLSH
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Resistance
Resistance is a property that slows the flow of electrons––the current. Using
the water analogy, resistance is an impediment to water flow. It could be a
smaller pipe or fins on the inside of a pipe. In electrical terms, the resistance
of a conducting wire is dependent on the metal used to make the wire, and
the diameter of the wire. Copper, aluminum, and silver––common metals used
in conducting wires––all have different resistance properties. Resistance is
a characteristic property of a conducting material.
Resistance is measured in units called ohms (W). There are electrical devices, called resistors, designed with specific resistance that can be placed
in circuits to reduce or control the flow of the current. Every electrical appliance contributes resistance to a circuit, as well. Any appliance or device placed
within a circuit to do work is called a load. The lightbulb in a flashlight is a
load. A television plugged into a wall outlet is a load. Every load introduces
resistance in a circuit.
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Ohm’s Law
George Ohm, a German physicist, made an important discovery about electricity in the early 19th century. He found
that in many materials, especially metals, the current that flows through a material is proportional to the voltage
across the material. In the substances he tested, he found that if he doubled the voltage (V), the current (A) also
doubled. If he reduced the voltage by half, the current dropped by half. The resistance (W) of the material remained
the same whether the voltage and current increased or decreased. This relationship is called Ohm’s Law, and can be
written in three simple formulas. If you know any two of the measurements, you can calculate the third using these
formulas:
voltage (volts) = current (amperes) x resistance (ohms)
or
V=AxW
current (amperes) = voltage (volts) / resistance (ohms)
or
A=V/W
resistance (ohms) = voltage (volts) / current (amperes)
or
W=V/A
Electrical Power
Power is a measure of the rate of doing work or the rate at which energy is converted. Electrical power is the rate at
which electricity is produced or consumed. Using the water analogy, electric power is the combination of the water
pressure (voltage) and the rate of flow (current) that results in the ability to do work.
A large pipe carries more water (current) than a small pipe. Water at
a height of 10 meters has much greater force (voltage potential)
than water at a height of one meter. The power of water flowing
through a 1-centimeter pipe from a height of one meter is much less
than water through a 10-centimeter pipe from a height of 10 meters.
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Electrical power is defined as the amount of electric current flowing
due to an applied voltage. It is the amount of electricity required to
start a device or operate a load for one second. Electrical power is
measured in watts (W). The formula for power that quantifies this
relationship is:
power (watts) = voltage (volts) x current (amperes)
or
W=VxA
Measuring electrical power can be confusing because a watt does not sound like a rate.
Usually we think of rates as ratios––miles per hour or miles per gallon. A watt is, in fact, a
ratio; you must learn about another measurement to understand it––a joule. A joule is a
measurement of work performed. One watt is the rate of doing work when one joule of
energy is used in one second (1 watt = 1 joule/second).
A 50–watt lightbulb uses electrical power at a rate of 50 joules per second. A 100---watt
lightbulb uses electrical power at the rate of 100 joules per second.
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Names:
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Can You Light the Light Bulb?
Data Collection Sheet
Diagrams
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Identify the type(s) of arrangements.
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affected by the number of bulbs
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through each bulb in a series circuit?
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What difference is there between
the current through the battery when
two bulbs are connected in series, and
the current through the battery when
two bulbs are connected in parallel?
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What supplied the voltage for all of the tasks that we did?
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What is voltage measured in?
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Electrical Circuits - An Introduction
As you arleady know, electricity
is the flow of electrons. Conductors are materials that
allow their electrons to move around. Metals are great examples of conductors. When
electrons flow, or move around, they need a pathwway to follow. This pathway is called an
electrical circuit. Typically, electrical circuits are a mixture of wires (conductors) and
things attached
to the wires (light bulbs, resistors,
motors, etc.). Today you are going to
learn how to draw simple electrical circuits.
Part One: The Symbols
If you look below, you will see the symbols that we use when we draw circuits. It isn't
important that you know what each of these things is right now, you just need to know
their symbols so you can draew them.
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Cell
SWitch
-1 I....~1Battery
-0- -0- --0Voltmeter
Lamp
~
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Motor
Resistor
Wire
•
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wire
Connection
t-- Switch
Ammeter
Part Two: Some Sample Circuits
The pictures below show an energized and a de-energized
circuit. When a circuit is
energized it just means that there is a continuous pathway for the electrons to follow. In
other words, you could trace the pathway with your finger without lifting your finger from
the page. Another name for an energized circuit is a closed circuit. Another name for a deenergized circuit is an open circuit. Look at the two circuits below.
1. What is the difference between the two circuits? Why is one energized and the
other not?
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Part Three: Drawing Some Circuits
Now it is your time to shine! Draw each of the circuits described below:
A. Draw a closed circuit that consists of wire, a battery and llight bulb.
B. Draw a closed circuit that consists of wire, a battery and two light bulbs.
c. Draw a closed circuit that consists of wire, a battery, a light bulb and a switch.
D. Draw an open circuit that consists of wire, a battery, a light bulb and an open
switch (look at the example circuits from earlier).
-E. Draw a closed circuit that consists of wire, a motor, a battery and a light bulb.
-
.
f. Draw an example of a closed circuit that wouldn't work (Hint: make it so no
electrons would be flowing).
\
( $""-
1 /
T
c:;
G. Draw a circuit that consists of wire, a battery and two light bulbs, where one light
bulb will keep working even if the other one burns out. (Hint: each light bulb will
need its own pathway for electrons to travel)
H. Draw a closed circuit that consists of wire, a battery,
two light bulbs and a switch
where, when the switch is closed, both lights are on and where, when the switch is
open, only one light bulb is on.
The Ohm’s Law Circuit Building Challenge
Hi! Today you are going to continue to learn about Ohm’s Law and Circuit Building. Along the way,
you will create circuits to meet various challenges that I give you. All in all, it should be a pretty
great day!
Background Information
As you already know, Ohm’s Law states the relationship between voltage, current and
resistance. The formula is
Current (amps) = Voltage (volts) ÷ Resistance (ohms)
The current is a measure of the flow of the electrons, the voltage is a measure of the force
pushing the electrons and the resistance is a measure of the friction in the circuit that is going
against the current. When you change any value in the equation (increase the voltage, change
the resistance, etc.), you have an effect on the rest of the values in the equation.
Getting Started
1. Log on to your computer.
2. Go to the following web site: http://phet.colorado.edu/en/simulation/circuitconstruction-kit-dc
3. Click on “Run Now!”
You now have the raw material to create a circuit. Take a moment to look over the site and find
all the different materials. To build a circuit you will need several wires, a light bulb, a voltage
source, a voltmeter, and a non – contact ammeter. Play with it to see how to grab and manipulate
these tools.
Click the reset button.
The Circuits
A. Series Circuits
Build a simple series circuit that consists of 6 pieces of wire, 1 light bulb, and 1 battery (voltage
source). In order to complete the circuit, the red circles at the end of each must overlap.
Please note that the light bulb also has TWO circles. Your circuit is complete and working when
the light comes on and the blue dots begin moving.
Draw a picture of your circuit here.
What do you think that the moving blue dots represent?
Use the tools at the side to get a voltmeter and a Non-contact ammeter. Put the voltmeter near
the battery and place the red tab at one end and the black at the other.
What is the voltage? __________
Place the ammeter crosshairs over the moving blue dots. What is the reading? _______
What does an ammeter measure? ____________
Go over your circuit drawing and label each wire with its ammeter reading.
Right click on the battery and choose the “Change Voltage “option.
Try different voltages and see what happens to the current in the circuit. Fill in the blanks
below:
As I increase the voltage, the current _________________.
As I decrease the voltage, the current _________________.
Right click on the light bulb and choose the “Change Resistance” option.
Try different values and see what happens to the current in the circuit. Fill in the blanks below:
As I increase the resistance, the current _________________.
As I decrease the resistance, the current _________________.
Click the reset button and begin the next challenge.
B. Parallel Circuits
Parallel circuits provide more than one path for electrons to move. Sketch below a parallel
circuit that includes 10 wires, 2 light bulbs and 1 voltage source.
Create this using the simulator tool. The blue dots will be moving and both lights will be on once
the circuit is complete.
Use the voltmeter to measure the voltage in the battery. Record the voltage here: _______
Use the non-contact ammeter to record the current in each of the wires. Write down the
readings on your circuit drawing.
What did you notice about the current reading in the parallel circuit that was different from
the series circuit?
What can you tell me about the current that each light receives?
The Challenges
For the remainder of the class, get through as many of the following challenges as you can. Take
this packet home and work on any challenges that you don’t finish. The further that you get in
the challenges, the more points that you will earn. If you complete all of the challenges, you will
earn extra credit.
Challenge #1
Make a light bulb light brightly using 4 batteries.
Draw your circuit below.
Challenge #2
Add an on/off switch to your circuit from Challenge #1.
Draw your circuit below.
Challenge #3
Make 3 light bulbs light brightly with all 3 with the same brightness (same current, measures
the same number of amps). Draw your circuit below, label the current for each light bulb.
Challenge #4
Add a switch to your circuit from Challenge #3 that will turn off 2 of the three lights. Draw
your circuit below.
Challenge #5
Move the switch in your circuit from Challenge #4 so that it turns off all three lights. Draw
your circuit below.
Challenge #6
Make a circuit that contains two switches, two bulbs, one battery and some wires. Make it so
that if either switch is open, neither light shines, but if both switches are closed, both lights
shine. Draw your circuit below.
Challenge #7
Make a circuit that contains two switches, two bulbs, one battery and some wires. Make it so
that if both switches are open, neither light shines, but if either switch is closed, both lights
shine. Draw your circuit below.
Challenge #8
Make a circuit with three light bulbs (bulb #1, bulb #2 and bulb #3). When you remove light
bulb #1, the whole circuit shuts down and when you remove bulbs two or three, the other bulbs
stay on. Draw your circuit below.
Challenge #9
Make a parallel circuit with two batteries and four lights. Make it so that the light bulbs each
shine with a different brightness. Draw your circuit below and explain what you did to make the
bulbs shine differently.
Challenge # 10 – Design your own challenge.
Make a circuit of your own design and write your own challenge statement (Just like you were
the teacher trying to challenge the rest of the class. Draw your circuit below and write your
challenge statement.
, Ohm's Law
Name:
Background Information
,
A German physicist, Georg S. Ohm, developed this mathematical
most circuits. This relationship
relationship,
is known as Ohm s law. This relationship
states
I
voltage (energy) in a circuit increases, so does the current
increases,
-----------which is present in
that if the
(flow of charges). If the resistance
the current flow decreases.
To work through this skill sheet, you will need the symbols used to depict
circuits in diagrams. The symbols that are most commonly used for circuit
diagrams are provided to the right.
If a circuit contains more than one battery,
the total voltage is the sum of
the individual voltages. For example, a circuit containing two 6 V batteries
has a total voltage of 12 V. (Note: The batteries
.~
)o.?
must be connected
positive to negativ~ for the voltages to add.)
If a problem asks you to calculate the voltage or resistance,
rearrange
you must
the equation I=V /R to solve for V or R. All three forms of
the equation are listed below
v = IxR
r
\
I=V
'k
R
"-If:t.- c~~~•..+
V
R=. I
.)~t'\G
Example Problem
If a toaster produces 12 ohms of resistance
in a 120-volt circuit, what is the ~mount of current
in the circuit?
Given
The resistance (R) is 12 ohms.
The voltaqe (V) is 120 volts.
Looking for
The amount of current (I) in the circuit.
Relationships
I = VIR
Solution
I = V /R
=
120 volts/12 ohms
The current
in the toaster
=
10 amps
is 10 amps.
Practice Problems
In this section, you will find some problems based on diagrams cmd others without diagrams. In
all cases, show your work.
1. How much current is in a circuit that includes a 9-volt batte:ry and a bulb with a resistance of
3 ohms?
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current.
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and a bulb with a resistance
of 3 ohms. Calculate the
current.
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7. How much voltage would be necessary to generate 10 amps of current in a circuit that has 5
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If the current in the CD player is 2 A, what is
its resistance?
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11. You have a large flashlight that takes 4 D-cell batteries.
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13. What happens to the current in a circuit if a 1.5-volt battery is removed and is replaced by a
9-volt battery?
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14. In your own words, state the relationship between resistance and current in a circuit.
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16. What could you do to a closed circuit consisting of 2 batteries,
increase the current? Explain your answer.
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18. You have four 1.5 V batteries, a to. bulb, a 2.a bulb, and a 30. bulb. Draw a circuit you could
build to create each of the following currents. There may be more than one possible answer
for each.
1 ampere
2 amperes
3 amperes
6 amperes
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America Revealed: Electric Nation
NAME: ________________
1. On average, how many electric devices are in our homes?
2. When was the first power plant made?
3. What is the name for the collection of power plants that are around the nation?
4. What connects all of the different power plants across North America?
5. How many miles of high tension transmission lines are there today?
6. What caused the blackout in the summer of 2003?
7. How many people in America were without power?
8. How do workers get to the high voltage lines to repair them?
9. What does it mean when they say that the lines are “live”?
10. How many volts were in the line?
11. How many generating plants do we count on to power the grid?
12. What type of power plants provide the most of our electricity?
13. What percent of our energy do we get from coal?
14. Where is the largest coal mine in the United States located?
15. Why makes the coal in Wyoming special?
16. How many tons of coal can one truck hold?
17. One truckload of coal could supply the energy needs of one household for how many
years?
18. How long will the Powder River Basin coal last?
19. When did the first nuclear reactor come on line?
20. How hot does the water get in the core of the reactor?
21. How many nuclear plants are in operation today?
22. What fossil fuel is seen as safer and cleaner than coal and nuclear?
23. How many times could our natural gas pipelines in the United States reach around the
earth?
24. How else, besides using pipelines, do we transport natural gas?
25. How cold is the gas kept while it is on the ship?
26. What new source of natural gas did they find in the United States?
27. What are the controversies with the natural gas in shale?
28. What is America’s fastest growing renewable resource?
29. How many wind turbines are there across America?
30. How tall are the wind turbines?
31. The energy produced by one wind turbine is enough to power ________ homes.
32. Where does most of the energy loss in America happen?
33. Who are the main electricity users in America today?
34. What do you think America’s energy future will look like? How will we meet our energy
needs?