Catapults and Shields
Spero, Cooper
Catapults and Shields (Double Period)
NJ Core Curriculum Standards
CCS Number
5.1.12.A.1
Topic
5.1 – Science Practices
A – Understanding Scientific
Explanations
5.1.12.A.2
5.1 – Science Practices
A – Understanding Scientific
Explanations
5.1.12.B.1
5.1 – Science Practices
B – Generate Scientific
Evidence Through Active
Investigations
5.1.12.B.2
5.1 – Science Practices
B – Generate Scientific
Evidence Through Active
Investigations
Description
Mathematical, physical, and
computational tools are used
to search for and explain core
scientific concepts and
principles.
Interpretation and
manipulation of evidencebased models are used to build
and critique
arguments/explanations.
Logically designed
investigations are needed in
order to generate the evidence
required to build and refine
models and explanations.
Mathematical tools and
technology are used to gather,
analyze, and communicate
results.
5.1.12.B.4
5.1 – Science Practices
B – Generate Scientific
Evidence Through Active
Investigations
Scientific reasoning is used to
evaluate and interpret data
patterns and scientific
conclusions.
5.1.12.C.3
5.1 – Science Practices
C – Reflect on Scientific
Knowledge
5.1.12.D.1
5.1 – Science Practices
D – Participate Productively
in Science
Science is a practice in which
an established body of
knowledge is continually
revised, refined, and extended
as new evidence emerges.
Science involves practicing
productive social interactions
with peers, such as partner
talk, whole-group discussions,
and small-group work.
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5.1.12.D.2
5.1 – Science Practices
D – Participate Productively
in Science
What Students Should Know
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Energy
o Kinetic energy
o System approach
o Gravitational potential energy
o Elastic potential energy
o Work
ISLE
Engineering Design Process
Science involves using
language, both oral and
written, as a tool for making
thinking public.
Catapults and Shields
Spero, Cooper
Goals of the Lesson
Conceptual
Energy is a conserved quantity.
Quantitative
Work-energy bar charts, workenergy conservation formulae.
Procedural
Consciously implementing the
engineering design process.
Epistemological
What part of the ISLE cycle is
this?
To understand energy you need
to define a system.
Size measurement of
construction, displacement of
projectile’s flight.
Work in groups effectively and
use materials effectively.
What parts of the engineering
design process did you use?
Identify which of your
activities correlate with parts of
the process.
In what ways were you aware
of the physics and engineering
behind aspects of your task?
Did it help?
Elastic potential energy is
another form of energy that can
come from deformation of any
object.
Breaking is transfer of internal
energy to kinetic energy.
Run an observational
experiment, come up with
assumptions and patterns.
Building of catapults and
shields involves engineering
disciplines from: civil,
mechanical, bioenvironmental,
and aerospace.
Engineering as a practice
involves focused planning.
The engineering process is
composed of research, design,
testing, redesign, and
communicating results.
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Catapults and Shields
Spero, Cooper
Important Details/Connections
Physics Content
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Energy
 Kinetic energy
 System approach (Work)
 Gravitational potential energy
 Elastic potential energy
Work-energy bar charts
Possibly rotational dynamics for trebuchet
Real Life Connections
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Dams
Modern weaponry
 Bullet-proof vests/shields
 Armor piercing rounds
Angry Birds
Carnival games
Bowling
Darts
Car windshields
Micrometeorite shielding
aurora borealis, aurora australis
Potential Student Difficulties
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Not knowing what a catapult is or any basic construction of one
Not knowing how to create a throwing mechanism
Not being able to identify steps in the engineering design process within actual building
Not understanding conservation of energy in system approach
Not knowing how to use work-energy bar charts
Difficulty relating exercises to engineering disciplines
Difficulty planning and building within time limit
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Catapults and Shields
Spero, Cooper
Resources
Environment

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Tables for groups to sit and work at
Indoors or shielded environment due to wind conditions
Equipment
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Playing Cards
Tape
Straws
Scissors
Rulers
Rubber bands
Pencils
Quarters
Lesson Description
Good afternoon everyone. Today, we’re going to be trying to recreate the popular game
Angry Birds. Who here can explain to the class the premise behind Angry Birds, and how you
achieve your goals inside the game
(Projectile flung into shield, crashes into shield trying to break shield, limited tries per
attempt at a specific shield configuration)
Ok, good, so now that we know the specifics about the game, how do you think we could
recreate the situations in the game? Could we create some type of shield to withstand the impact
of a projectile? Take a look at the handout in front of you. On it, you’ll see a list of available
materials. I want you split into groups of four or five, and take a look at the hand out. Take about
5 minutes to complete the first few portions of the engineering process.
(Students have 5 minutes to look over the material list and come up with designs for
shield and catapult system, but do not have the material yet. Emphasis on having students sketch
their ideas on paper, using words to describe and plan rather then simply ‘doing’)
Everyone, you should now have a pretty good idea about what kind of machine you will
build. Come get your materials, and start building. You have approximately 30 minutes, after
which time, we will all demonstrate our systems to the rest of the class. Begin!
(Allow 30-35 minutes for group construction. Circulate around room, checking on
student progress, following up on Formative Assessments 5-8)
All right everyone, there is about ten minutes left in the period. By now, you should all
have your designs built, tested, and if needed, reimagined. Let’s show our designs to the rest of
the class. Then pick another group to test your launcher and shield with.
(Go around in a circle, having each group show off their design, talk a bit about where
their design idea came from, and what redesigns they made go through, check formative
assessment 9.)
Lesson Part the Second
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Okay, now that we’ve seen how the projectile is flung, let’s try to identify exactly what
happened, and what we saw. As you remember, we’ve been dealing with energy, and how the
energy of a system is conserved, so what I want you to do now, individually is to draw an energy
bar chart and pick the first instant as just when you release the projectile, but before it has moved
and the second point wherever you wish. Do you notice anything odd? Or is there something you
are having difficulty with? Compare with a neighbor.
So far we have only discussed 2 forms of energy: kinetic energy and gravitational
potential energy of the system. Now depending on what system you chose your bar charts will
have different columns. But in many of your second instants I see kinetic and gravitational
potential energy, but nothing in the beginning. Where did the system get the energy from?
(If students say work, then ask them to elaborate and identify the two objects exerting
forces on one another that causes the work to be done on the system. If students have mechanism
inside system then bring up the possibility of a new form of energy. Ask them to name this
themselves.)
What realistic situations can you think of that are similar to this? That involves this new
form of energy? What do these situations have in common? Why do you think this type of
energy exists? Come up with a way to quantitatively figure out the mathematical form of this
new type of energy with your catapult.
Catapults and Shields
Spero, Cooper
Time Table
Clock Reading During
Lesson
0-5 minutes
Title of Activity – Connection
Students Doing
to Goals
Hook-Angry Birds
Listening
5-10 minutes
Planning
10-40 minutes
Building/Testing/Redesigning
40-50 minutes
Symposium
50-55 minutes
Testing
55-60 minutes
What Would I Change?
60-75 minutes
Bar Charts
Teacher Doing
Setting up situation for
students, handing out dittos
Looking at materials list and
sketching possible plans for
catapult and shield
Building, testing, redesigning
and filling in worksheet for
engineering design process
steps
Students discuss as a class their
thought process and how their
design changed from beginning
to end and why and go around
from group to group
Seeing if catapult or shield
works to specifications
Showing materials and making
sure students are planning and
writing
Going around and helping
students with specific tasks like
cutting or getting materials, not
helping with design or redesign
Holding symposium timing,
leading questions, bringing out
engineering design process
Taking 5 minutes to write
down what further changes
would be made to design.
Constructing work-energy bar
charts for 2 instances in
projectile’s flight, comparing
with neighbors’
Make sure everything is
written down on worksheet.
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Recording observations
Helping students who have
difficulty making bar charts
and identifying types of energy
in each situation or choosing a
system
75-80 minutes
Something Missing
80-90 minutes
ISLE Obs Exp.
Trying to figure out what is
missing or wrong from workenergy bar charts. Anything
unexplainable.
Coming up with a quantitative
observational experiment to
investigate new form of energy
Leading questions.
Asking students to come up
with name for new form of
energy and asking them to
come up with experiment.
Catapults and Shields
Spero, Cooper
Formative Assessments
1. Can students construct a work-energy bar chart?
a. Define a system
b. Kinetic, GPE
c. Unknown energy
2. When not knowing about EPE, will students see in their charts that something is missing?
3. Ask students for ideas of what in or out of the system has energy that is transferred to the
projectile.
4. Can students list other materials or devices than can act similarly in transferring this kind
of energy?
5. Is worksheet filled out with engineering design process steps?
6. Have students identified what kind of ISLE cycle experiment this is?
7. Students can identify at least 2 different disciplines of engineering involved in process.
8. Can students construct a working catapult and shield?
9. Does catapult and shield fulfill requirements and goals
10. Can students use work-energy bar charts to come up with a quantitative observational
experiment for elastic potential energy?
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