National Science Foundation
North Mississippi GK-8 Project
University of Mississippi
http://smartweed.olemiss.edu/nmgk8
NSF North Mississippi GK-8
What is NMGK-8?
The North Mississippi grades K through 8 (NMGK-8) project, in
part funded by the National Science Foundation, places
graduate students from Science, Technology, Engineering and
Mathematics (STEM) into the city of Oxford and Lafayette
County schools as resources for the local teachers.
The NSF fellows participate in interdisciplinary teams to locate
and/or develop materials to be utilized in elementary and
secondary science and mathematics classrooms. The project’s
goal is to enhance the educational practices in use by K-8
teachers and students with emphasis on materials that
improve critical thinking skills, effectively reaching students in
every grade, academic performance level, cultural background
and learning style.
As often as appropriate, the curriculum will utilize the
Mississippi River as the conceptual "umbrella" under which a
variety of lessons and activities may be developed. By crafting
many activities and problems around a single conceptual
theme, students will grasp the variety of disciplines that are
actively involved in any given study as well at the intertwining
of skills and content that such studies require.
Every project developed by the NMGK-8 fellows covers at least
one Mississippi Mathematics or Science Framework and then
is paralleled to its corresponding National Benchmark.
The website currently houses 124 projects for Kindergarten –
8th grade.
NSF North Mississippi GK-8
How do I access projects on the NMGK-8 website?
1. Log on to http://smartweed.olemiss.edu
2. Under the “For Teachers” topic, click on projects.
3. Two ways to find projects:
a. Specific grade and subject
i. Choose a grade and subject
1. To choose more than one grade or
subject, hold down the control key.
ii. Click view selected
b. Viewing all
i. Click View All Projects
What else is available on the NMGK-8 website?
Other teacher resources on the website include:
A complete list of the Mississippi Math and Science
Frameworks:
1. Under “For Teachers,” click on frameworks
2. Choose a specific grade and subject or view all.
3. Each framework is linked to a page which gives the
description of the framework, the correlated national
standard, and the link to any projects that include those
frameworks.
A list of helpful math and science websites:
1. Under “For Teachers,” click on Web Resources.
2. A useful list of websites will be displayed.
a. Categories include:
Websites for ordering materials
Resources and lesson plans
General Web resources divided in subject areas.
A complete search engine of our website:
1. Under “Project Search,” you can type in any keyword
from a project idea to a keyword in a framework.
2. A list of projects will be displayed that contain that
keyword.
NSF North Mississippi GK-8
A comments page:
1. Under “For Teachers,” click Send Feedback.
2. Fill in your name, email address, and comments.
****NOTE: Please use this feature! NSF wants to hear how
and where our projects are being used and if they were
beneficial to other teachers.****
Lists, pictures, and contact information of our team.
NSF North Mississippi GK-8
Physics of a Half Pipe
Intended for Grade: Seventh
Subject: Math and Science
Description: This project uses skateboarding and a miniature
skateboarding half pipe to illustrate the concept of conservation of energy
and energy transformation.
Objective: The students will be able to recognize the role that the
conservation of energy plays in a real life example.
Mississippi Frameworks addressed:
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Math Framework 1b: Add, subtract, multiply, and divide
decimals in real-life situations with and without calculators.
Math Framework 3a: Convert within a standard
measurement system (English and metric).
Math Framework 3c: Use standard units of measurement to
solve application problems.
Math Framework 4e: Estimate and compare data including
mean, median, mode, and range of a set of data.
Math Framework 7d: Write and solve equations that
represent problem-solving situations.
Science Framework 9c: Using the scientific method, design
and experiment to test how different types of surfaces affect
friction.
National Standards addressed:
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Math Standard: Numbers and Operations
Math Standard: Connections
Math Standard: Measurement
Math Standard: Problem Solving
Math Standard: Data Analysis and Probability
Math Standard: Algebra
Content Standard A: Science as Inquiry
Content Standard B: Physical Science
NSF North Mississippi GK-8
Materials:
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Tony Hawk video
Several pieces of thin cardboard such as flattened cereal,
cracker, or tissue boxes
Cardboard boxes
Tape
Glue
Metric rulers
Markers
“Physics of a Half Pipe: Experimental Data” sheet
Triple beam or analytic balance
Marbles
Background:
Skateboarding has seen an immense growth in popularity over the
last several years. What started as a way for surfers to kill time when
the waves were not high enough for surfing has turned into an organized
competitive sport that boasts internationally known athletes and a
million dollar industry. Skate parks have sprung up around the country
and the world, and skaters have developed their own distinct subculture.
One of the things that make skateboarding so exciting to many is
the variety of complicated tricks that skilled skateboarders can perform.
To an amateur these tricks seem to defy the laws of physics. However,
skateboarding, in fact, provides ideal examples for studying physics,
because skateboarding tricks are actually dramatic demonstrations of
physics principles in action. Many skateboarding tricks could be used to
illustrate different physics principles, but one of which is the
conservation of energy in a skateboarding half pipe.
A half pipe is a curved structure shaped like the bottom half of a
large pipe and used in snowboarding, free-style biking, and
skateboarding. In a half pipe, skaters gain speed by rolling up and down
the opposite sides, eventually launching above the lip of the pipe and
performing tricks in the air. One way physics comes into play in the half
pipe is with the principle of conservation of energy. This principle states
that energy cannot be added or subtracted from the original energy of a
system.
Energy can, however, be transformed between forms. The primary
forms of energy that skaters have in a half pipe are potential and kinetic
energy. Potential energy is stored energy related to height. When
skaters are at the top of the ramps, they have the highest amount of
potential energy. Kinetic energy is energy of motion. The faster skaters
are moving, the more kinetic energy they have. In a half pipe energy is
NSF North Mississippi GK-8
constantly transformed between potential and kinetic energy as the
skater goes back and forth between the ramps.
The conservation of energy says that the total amount of energy
involved in the transformation must remain constant. The question then
is why the skater eventually slows down and stops. This is because
there is another energy transformation involved: kinetic energy is
transformed into heat by friction. Eventually so much kinetic energy will
have been transformed into heat energy that the skater will come to a
stop. Even though the energy has changed forms and the skater is no
longer moving, the energy of the system has remained constant.
However, when skilled skaters use a half pipe, they seem to violate
this principle. They can skate for long periods of time without slowing
down at all. In fact, the skaters often increase their speed. Where does
this extra energy come from?
The answer is that skaters use the energy of their own body.
Skaters do something called “pumping.” On a half pipe, skaters will
crouch slightly to lower their center of mass. They will then stand up
when approaching the ramp. The energy in the skater’s body needed to
push up against the skateboard causes the speed to increase. This same
principle is used when someone on a swing pumps his or her legs to go
higher. If skaters do not pump, eventually friction will cause them to
lose speed.
It is possible to measure how much energy is lost to friction by
measuring the differences in height the skater reaches on the ramp. By
measuring the height the skaters start from, their initial potential energy
can be calculated. Potential energy is given by the equation E = mgh,
where h is the height of the skater in meters, g is the acceleration due to
gravity (9.8 m/s2), and m is the mass of the skater in kilograms. Energy
is measured in units of kg x m/s2 or Joules.
When the skaters roll down the ramp, their potential energy is
converted into kinetic energy. As they roll up the opposite side, this
kinetic energy, minus that lost to friction, is in turn converted back to
potential. By measuring how high they roll back up the ramp, their new
potential energy can be found. The difference between this energy and
their initial energy is the energy transformed into heat by friction.
Procedure:
1. Ask the students what they know about skateboarding. If there are
any skateboarders in the class, have them share some of their
experiences.
2. Explain that skateboarding is a good way to study physics because
many of the impressive tricks skateboarders can perform are actually
excellent demonstrations of physics principles.
NSF North Mississippi GK-8
3. Introduce the students to the half pipe and show the included
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skateboard footage.
Tell the students that they will be constructing their own miniature
half pipes to learn about the conservation of energy.
Explain that the conservation of energy states that the energy of a
system remains constant. This means that the energy a system starts
with must be the same as the energy with which it ends.
Explain kinetic and potential energy. Ask the students where a skater
on a half pipe will have the highest and lowest kinetic and potential
energies.
Divide the students into construction teams of two to four students.
Show the students a pre-made model half pipe and allow them to use
the cardboard, glue, scissors, tape, and other materials to construct
their own group half pipe.
Have the students mark their half pipes with height markings along
one ramp at intervals of one centimeter or one half centimeter. Be
sure to explain and, if needed, demonstrate that they are not
measuring distance along the ramp but height of the ramp above the
base of the cardboard box.
Pass out one marble to each group and explain that the marbles will
represent skateboarders on their half pipes.
Have a member of each group release the marble from the edge of the
half pipe.
Ask the class to explain the behavior of the marble. What kind of
energy did it have when it was rolling? (Kinetic) What kind of energy
did it have when it paused on the ramps? (Potential)
Explain that as the marble moved between the ramps it was
transforming energy between forms but that the total energy of the
marble-half pipe system must remain constant.
Ask the class why the marble did not keep rolling between the two
slopes indefinitely. If conservation of energy holds, why does it appear
as though the marble lost energy and slowed down? Ask the students
where they think this missing energy went.
Explain that the rolling marble had friction with the cardboard it
rolled against and the air it rolled through. This friction eventually
transformed the marble’s kinetic energy into heat energy. Though it
was too slight too feel, the half pipe was warming up. Energy was not
actually lost; it was converted to another form.
Tell the students that their task is to determine how much energy was
converted to friction during the first complete “transit” of the half
pipe. A “transit” is the path a marble takes as it is released from one
side, travels up the opposite side, and then returns to the side where
it was released.
NSF North Mississippi GK-8
17. Pass out the “Physics of a Half Pipe: Experimental Data” sheet to the
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students. This will give them clues about how to determine the
amount of energy lost.
Remind the students to carefully watch the units of the formula and
compare them with the units they are measuring.
Allow the groups to work through their procedures and complete the
data sheet. Compare results as a class.
Now that the students have seen the conservation of energy in action
in the half pipe, show the provided skateboarding footage once again.
Ask the students whether the skateboarder behaves in the same way
as the marble did when released in the half pipe. Does he appear to
be slowing down and eventually stopping?
The skateboarder actually appears to be maintaining a certain speed
or even increasing his speed. Ask the students if this violates the
conservation of energy principle. Why does friction not slow down the
skater like it did the marble?
Explain that the skater is using the energy in his own body to
maintain his speed. This does not violate the conservation of energy
principle because the energy in his body is already a part of the
system.
Point out how the skater lowers himself near the bottom of the half
pipe and stands straight up as he approaches the ramp. This is
called “pumping,” and the action of raising and lowering his center of
gravity works in much the same way as pumping your legs on a swing
makes you go higher.
Evaluation:
The students work together in constructing a model half pipe and
participate in class discussion of the covered topics. They indicate
comprehension by determining the proper method for calculating energy
lost to friction. Finally, they correctly complete the “Physics of a Half
Pipe: Experimental Data” sheet.
Extended Activities:
For those classes in Mississippi, the physics principles introduced
in this lesson may be explored further at the new Oxford Skate Park.
The park is located across from the public library just off University
Avenue. This nearly 10,000 square foot skate park should be completed
by late spring of 2006 and is designed to have an area that will function
much like the half pipe described in this lesson. More information and
design images can be found at the website listed below as well as links to
other Mississippi skate parks.
NSF North Mississippi GK-8
Besides pumping on a half pipe, there are two other basic
skateboarding tricks that nicely demonstrate general physics principles.
An “ollie,” the first trick most skateboarders learn, demonstrates friction,
sum of forces, and rotation to make the skateboard leap into the air,
seemingly glued to the skater’s feet. A 360, where a skater spins in the
air without pushing off against anything, provides an elegant
demonstration of the conservation of angular momentum. Further
explanations and images can be found at the Exploratorium website
listed below.
Plan a trip to a skate park with an experienced skater who can
perform the tricks discussed. Have the students film the tricks. Back in
the classroom, replay the videos at low speeds. By watching the videos
and using basic physics principles, have the students explain step-bystep the physics behind the tricks. The students could present their
findings in a poster, website, or PowerPoint presentation.
Use the miniature half pipes to study the way different surfaces
affect friction. For example, compare how energy lost to friction on a half
pipe with its surface covered in saran wrap compares to energy lost on a
half pipe covered with sand paper. Experiment with a variety of surfaces
to see what causes the most friction and what causes the least friction.
Sources:
City of Oxford, Mississippi, The. 2005. “Oxford Skate Park: Construction
Underway.” Accessed 5 January 2006.
<http://www.oxfordms.net/recent/skatepark.htm>.
Doc*36 Skate Park. 10 December 2005. “Christmas Holiday Schedule.”
Accessed 5 January 2006. <http://www.doc36skatepark.com/>.
Robinson, Lowell. “Exploratorium: Skateboard Science.” Accessed 5
January 2006.
<http://www.exploratium.edu/skateboarding/index.html>.
Southcoast Skate Park. 23 December 2005. “South coast will re-open in
June 2006.” Accessed 5 January 2005.
<http://www.southcoastskatepark.com/>.
Prepared by:
Steve Case
NSF NMGK-8
University of Mississippi
January 2006
NSF North Mississippi GK-8
Discovering Newton’s Laws of Motion
Intended for Grade: Eighth
Subject: Math and Science
Description: This project consists of a lesson introducing Newton’s
three laws of motion, comprehension quizzes accompanying each of the
laws, simple demonstrations illustrating each law, and a design project.
Objective: The students will be able to relate the application of
Newton’s Laws of Motion through the design and construction of a
rubber band powered vehicle.
Mississippi Frameworks addressed:
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Science Framework 9a: Apply and demonstrate Newton’s
Three Laws of Motion using simple machines.
Science Framework 9b: Design and construct simple and
complex machines.
Science Framework 10d: Convert one energy form to
another.
Math Framework 1d: Solve real-life problems involving
addition, subtraction, multiplication, and division of fraction,
decimals, and mixed numbers.
Math Framework 1g: Add, subtract, multiply, and divide
integers and rational numbers with and without calculators.
Math Framework 3c: Convert between word phrases or
sentences and algebraic expressions, equations, or
inequalities.
Math Framework 3d: Simplify and evaluate numerical and
algebraic expressions.
National Standards addressed:
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Content Standard A: Science as Inquiry
Content Standard B: Physical Science
Math Standard: Number and Operations
Math Standard: Connections
Math Standard: Problem Solving
Math Standard: Algebra
Math Standard: Communication
NSF North Mississippi GK-8
Materials:
Demonstration 1: Newton’s 1st Law
 A small bowl with water in it
 An empty table top
Demonstration 2: Inertia and Mass
 Two small, identical cardboard boxes, such as instant
oatmeal or Hamburger Helper boxes
 One quart-sized Ziploc bag, filled approximately ¾ full with
water and placed inside one of the boxes
 A table
Demonstration 3: Newton’s 3rd Law
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Tennis Ball
Table
One textbook, preferably a larger one such as a history book
or similar
Activity: Rubber Band Car Design and Competition
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Student copies of the sheet “Rubber Band Car Guidelines”
Duct tape
Blank CDs
Pencils
1 bag of No. 12 rubber bands
Tape measure
A long empty hallway of the school, preferably with either
linoleum or bare floors
Other: materials students request after Day 1
Background:
Newton’s 1st Law
Definition: “If there are no forces on a body, that body will stay at rest
and a body that is moving at a constant velocity in a straight line will
continue to do so unless it is acted upon by another force.”
Newton’s first law is also called the law of inertia. A force is
something that causes or changes motion. A force can be applied to an
object at rest that causes that object to move, or it can be applied to a
moving body that causes that body to change direction or speed. A force
is not needed to keep an object in motion.
Inertia and Mass
Definition: “Inertia is the tendency of an object to resist changes in its
state of motion (velocity).”
NSF North Mississippi GK-8
Inertia is one of the few quantities that are dependent only on
mass. Thus, the greater the mass of an object, the greater its inertia, and
the more likely it is to resist changes in its state of motion.
Balanced and Unbalanced Forces
An informal way to state the 1st law is to say “objects keep on doing
whatever they were doing” unless they are acted upon by an unbalanced
force. A balanced force can be represented by Figure 1 below:
Figure 1. Balanced and Unbalanced Forces.
The forces are acting opposite each other and are equal in
magnitude; therefore the book is in equilibrium and does not move. An
unbalanced force pair is any that is not equal in magnitude and opposite
in direction. Objects tend to resist changes in their state of motion, i.e.
they “keep on doing whatever they were doing” unless acted upon.
In the real world objects do not travel forever without stopping.
What types of forces are acting upon an object in the real world? Take a
look at Figure 2:
Figure 2. Unbalanced Forces. The book is in motion moving to the right.
The forces in the vertical direction are balanced, with gravity
pulling down and the table pushing upwards. The book is moving
however, and there are no forces acting to the right (remember a force is
not needed to keep an object in motion). The only other force is friction,
NSF North Mississippi GK-8
which is acting to the left. The force of friction is an unbalanced force, so
as a result the book will experience a change in its state of motion. This
change is a deceleration (decrease in velocity) of the book. A summary of
balanced and unbalanced forces is presented in Figures 3 and 4,
respectfully.
Figure 3. Balanced Force Chart.
Figure 4. Unbalanced Force Chart.
Newton’s 2nd Law
Definition: “The acceleration of an object as produced by a net force is
directly proportional to the magnitude of the net force, in the same
direction as the net force, and inversely proportional to the mass of the
object.”
What does this mean? In simpler terms, it means that a net force
on an object will cause an acceleration of that object. Newton’s 2nd law
can be represented by the simple equation F = ma. Rearranging for a, we
find that a = F/m. From this equation we see that the force, F, on an
object is directly proportional to its acceleration, a. We also see that the
mass, m, of an object is inversely proportional to the object’s
acceleration. This means that if the force on an object is increased, its
acceleration will likewise increase, and if the mass is increased its
acceleration will decrease. The unit of force is the Newton (N): 1Newton =
1 kg-m/s2.
Clarification: As mentioned before, a force is not needed to keep an
object in motion. This common misconception can be clarified by
considering Figure 5, where the mass on a frictionless surface is being
acted upon by the two diagrammed forces. Is the object in motion?
NSF North Mississippi GK-8
Figure 5. Arbitrary block of mass M.
The object could be in motion. Hard to believe? This is a common
misconception about Newton’s laws. As drawn in Figure 5, the forces
currently acting on the mass are balanced, so no unbalanced force acts
on the mass. But it could be traveling at a constant velocity as the result
of an earlier force applied to it. Remember, from the definition of the 2nd
law, F= ma, so forces do not directly cause velocity, they cause only
acceleration. Thus, if there are no other forces acting on the object, it
could be moving at a constant velocity.
Newton’s 3rd Law
Definition: “For every action, there is an equal and opposite reaction.”
This is also known as the law of reaction. The law means that in
every interaction that occurs there is at least one pair of forces that act
on the object. These forces are balanced forces, meaning they are equal
in magnitude and opposite in direction.
Many times multiple force pairs occur during a given motion of an
object. A force pair can be any action-reaction pair, such as your foot
kicking a ball (action) and the ball pushing backwards onto your foot
(reaction). Figure 1 shows a simple force pair. The book is pulled
downward by gravity, and the table pushes upward on the book with a
force equal to that of the book pushing downward. The important thing
to remember is that every interaction produces an action-reaction
force pair.
NSF North Mississippi GK-8
Procedure:
Demonstration 1: Newton’s 1st Law
1. Teach the principles of Newton’s 1st Law and Inertia and mass
using a chalkboard and the diagrams in the background
section.
2. With the bowl of water in hand, slide it around on a table at a
constant speed.
3. Stop the bowl suddenly with your hand.
4. Ask the students to explain why the water did not splash when
the bowl was in motion but did splash when it was stopped. The
reason for the splash is that the water resisted changes in its
motion. Thus if the bowl was at rest and was suddenly moved,
water would spill. The same happened here when the bowl was
in motion and was suddenly stopped.
Demonstration 2: Inertia and Mass
This demonstration should be done right after Demonstration 1.
1. After teaching the students about inertia and mass, bring out
the two boxes and place them on a table. Inform the students
that one of the boxes has a bag of water in it while the other is
empty.
2. Ask the students how they could tell which box has the water in
it without lifting the boxes.
3. Students’ response should be to give each box a push. The box
that moves easier is the one with less inertia, and is thus
lighter, since inertia is solely dependent on mass. A common
wrong answer might be to push the box at the top and the one
which one falls over easier is the empty one. This is an incorrect
answer because this does not relate to Newton’s Laws; rather it
deals with lowering the box’s center of gravity by adding water.
4. Allow one student to come to the front and try this.
Demonstration 3: Newton’s 3rd Law
1. Teach the students about Newton’s 2nd and 3rd laws and about
force pairs using a chalkboard and the diagrams in the
background section.
2. Stand a textbook on end on the table.
3. Throw the tennis ball at the textbook with just enough force to
knock the book over. This may take several attempts.
4. Ask the students to identify the force pair(s).
NSF North Mississippi GK-8
5. One correct force pair is the ball pushing on the book, and the
book pushing back on the ball. Either of these can be the
action-reaction force. There may be other pairs that the
students can identify. This demonstration is diagrammed below
in Figure 6.
Figure 6. Ball thrown against a book.
Activity: Rubber Band Car Design and Competition
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Divide the class into pairs.
Distribute “Rubber Band Car Guidelines”.
Review the guidelines with the students.
Remind them to consider Newton’s Laws when building their
cars. This includes Newton’s 1st law: too much friction is bad,
because it results in an unbalanced force which will slow their
car down. Their design relates to Newton’s 2nd law because a =
F/m. This means that mass should be minimized. The 3rd law
can relate to the propulsion of their cars: whatever they do to
make it go forward, they will have to consider what the opposite
effect will be.
Show the class the sample rubber band car to give them some
ideas for design while stressing the importance of creativity for
their own design and that they are NOT to copy the sample car.
Allow them to witness a sample run.
Allow the students to work with their partner for the rest of that
class period and two more subsequent class periods. After the
first workday, if the students need special materials, tell them
to bring them to the next class period. Ideally these workdays
would be a Tuesday, Wednesday, and a Thursday.
Before class starts on the day after the last work day, set up a
“start line” near the end of the chosen hallway.
Measure off increments of 5 feet from the start line and mark
the increments with a piece of duct tape with the distance from
the “start line” labeled.
NSF North Mississippi GK-8
9. Allow one pair of students to line up at the “start line” with their
car and allow them to run it. Measure the distance and record
it.
10. Repeat until all the students have run their cars.
11. Repeat steps 8-9 again a second and third time so that each
pair of students gets 3 runs total.
12. Average the runs for each pair of students.
13. The pair of students that achieve the farthest distance on a
single run is one winner. The pair that achieves the highest
average of the three runs is another winner.
Evaluation:
The quizzes “Test Your Newton Knowledge!” can be given after the
first day of instruction or at the beginning of the second day. The quizzes
can be either given individually, or the complete set can be given at one
time. The distance contest can also serve as a tool for assessing the
students’ performance on the design portion of the project.
Extended Activities:
Conduct a second design competition requiring students to build a
car that covers a given distance, 10 to 15 feet, in the shortest amount of
time. This drastically changes the design requirements of the car. The
students would have to come up with a new design that obtains
maximum acceleration and maintains a fast speed.
A PowerPoint presentation discussing Newton’s Laws of Motion has
also been prepared to go along with this project. It may be helpful to
present this to the class before conducting the activity or afterwards as
review to give the students further practice with the Laws of Motion. A
worksheet to go along with the PowerPoint is included in the project.
Sources:
Science Education Partnerships: Ask A Scientist/Oracle. 10 September
2003. Mousetrap cars and rubber band cars. Accessed 25 June
2005. < http://www.seps.org/cvoracle/faq/mousetrap.html >
Stern, David P. March 2005. From Stargazers to Starships: (16)
Newton’s Laws of Motion. Accessed 5 July 2005.
<http://www.phy6.org/stargaze/Snewton.htm>
The Physics Classroom. 2004. Newton’s Laws. Accessed 5 July
2005. <http://www.physicsclassroom.com/Class/newtlaws
/newtltoc.html>
NSF North Mississippi GK-8
Prepared by:
Matt Aufman
Steve Case
NSF NMGK-8
University of Mississippi
July 2005
NSF North Mississippi GK-8
Test Your Newton Knowledge!
Newton’s 1st Law of motion
1. You are an astronaut in space far away from any gravitational field,
and you throw a rock as hard as you can. The rock will:
a. slowly slow down and stop
b. continue at the same speed forever
c. continue to accelerate at the rate it was when it left your
hand
Explain your answer.
2. If you were in a completely weightless environment, would you need a
force to make an object at rest start to move? Explain your answer.
3. Mrs. Kincade and her classes are playing putt-putt. One of the holes
looks like the drawing below. The golfer must use the metal rim to guide
the ball toward the hole. Mrs. Kincade guides hers around the rim as
shown. When the ball leaves the rim at the opening, which path will the
ball follow, and why?
4. True or False:
A car moving with a force of 2000 N runs straight into a dumpster
with a mass of 2000 N sitting on a frictionless surface. When the car hits
the dumpster it bounces backwards because the dumpster applies a
force equal in magnitude and opposite the direction in which the car was
moving. Explain your answer.
NSF North Mississippi GK-8
Newton’s 2nd law of motion
1. If you were to apply a force of 15N to a medicine ball that weighs 5 kg,
what would its acceleration be? How about one that weighs 10kg?
2. If Mrs. Kincade throws your graded homework assignment at you with
a force of 8N, and the homework accelerates at 5 m/s2, what is the mass
of the homework?
3. You are playing baseball and the ball is accelerating at 5m/s2 off your
bat. If the original net force of 5N is tripled, and the original mass of 1 kg
is doubled, what will be the ball’s new acceleration?
Hint: a= F/m.
4. Take the same baseball as above, accelerating at the same 5m/s2. If
the original net force of 5N is tripled, and the original mass of 1 kg is
halved, what will the new acceleration be?
Hint: a= F/m.
NSF North Mississippi GK-8
Newton’s 3rd law of motion
1. While driving over here to teach you this physics lesson, I watched as
a bug hit my windshield. I knew immediately that this was a
demonstration of Newton’s 3rd law, because the bug hit my windshield
and my windshield hit the bug. The question is which of the two forces is
greater: the force on the bug or the force on my windshield?
2. You are playing paintball with a friend. When you fire the paintball
gun, it recoils slightly. As it is fired, the compressed air from your CO2
canister pushes the paintball forward, and the paintball pushes your gun
backwards. The acceleration of your paintball gun is:
a. greater than the acceleration of the paintball.
b. equal to the acceleration of the paintball.
c. less than the acceleration of the paintball.
Explain your answer.
3. Study the drawing below between the two soccer players and the ball.
All three events are occurring at the same time. Identify the two pairs of
action-reaction forces. (Note: it does not matter what force is the action
or the reaction.)
NSF North Mississippi GK-8
Test Your Newton Knowledge! Quiz Answers
Newton’s 1st law:
1. The answer is (b), continue at the same speed forever. This is the
definition of the 1st law.
2. Yes! Even weightless, the object still has mass and thus inertia.
You still need a force to overcome inertia
3. The ball will follow path (2). The ball will continue to follow its
natural “inertial path”, and because of the lack of unbalanced
forces it will move in a straight line.
4. False. When the car hits the dumpster, the forces to the left are
balanced with forces to the right, so the car will continue in motion
in the direction it was coming from. The car would only bounce
backwards if the dumpster exerted more force than the car was
exerting.
Newton’s 2nd law:
1.
2.
3.
4.
F= ma, thus for a 5 kg ball, a=3 m/s, and a 10kg ball, a= 1.5 m/s.
F=ma, thus m= 1.6 kg.
a=F/m, so multiply by 3 and divide by 2 to get 7.5 m/s2.
a=F/m, so multiply by 3 and divide by .5 to get 30 m/s2.
Newton’s 3rd law:
1. The forces are the same. This is the definition of the 3rd law. The
bug just has a smaller mass and cannot withstand the larger
acceleration of the windshield.
2. The answer is (c), less than the acceleration of the paintball. The
forces are the same, but because the gun has a much larger mass
than the paintball, the acceleration of the gun will be smaller.
3. The action-reaction forces are:
a. Foot A exerts a force on ball B to the right, and ball B exerts
a force equal in size to the left on foot A.
b. Foot B exerts a force to the left on ball B, and ball B exerts a
force equal in size to the right on foot B.
NSF North Mississippi GK-8
Rubber Band Car Guidelines
You will be working with a partner to design and construct your own
rubber band powered car. The car should be designed as to maximize
distance traveled with the energy stored in its rubber band. There will be
no time stipulations on the race, so each car may move as slowly as
desired. Design criteria:
1. Only one rubber band will be allowed to power your car. If the
one you are given breaks, you will be given another.
2. The models will be no more than 12” wide.
3. Nothing that was designed for or previously used as a wheel is
allowed. This includes things such as Lego wheels, matchbox
wheels, or any kind of preformed wheel.
4. Ideas for allowable wheels include CDs, DVDs, bottle caps,
plates, plastic/metal/wood lids of various sorts, etc.
5. You will have access to various kinds of tape, pencils, and small
nails. If you need any other materials you must bring them
yourself or specifically request it after the first day.
6. Each pair of students will be allowed three runs of their car. A
run consists of a windup and a release of the rubber band car.
If your car spins out and only travels a foot that still counts as
a run.
7. The longest of the three runs will be the one that is used to
determine a winner. The pair with the highest average of their
three runs will also be a winner.
8. Be creative! Points for creative and interesting designs will be
awarded, even if they do not work as desired.
NSF North Mississippi GK-8
Name: _______________________________
PowerPoint Worksheet
on
Newton’s Laws of Motion
For what is Sir Isaac Newton famous? (You can list more than one
thing.)
What is needed to change the motion of an object?
Pushing your friend on a swing is an example of a balanced or
unbalanced force?
Inertia is the ___________________ of an ____________________ to
resist ____________________ in its state of ___________________.
Which would have more inertia: a box filled with air or a box filled with
cement? (Hint: which would have more mass?)
What can you do to double the force of a certain thrown ball? (There can
be more than one answer.)
What is an example of Newton’s Third Law you experience in your daily
life?
NSF North Mississippi GK-8
NSF North Mississippi GK-8