IPS Kick Off
Welcome to your IPS Kick Off project. This project is going to allow you to show off
what you learned in middle school as well as give you a more thorough understanding
of what you may already know.
Your goal:
 Design, construct, test and modify a marshmallow catapult. (You may have
done something like this in middle school but now the expectations are higher!)
 You should design a catapult that has two functions: great range and accuracy.
Steps:
I.
Brainstorm: how you can create a catapult with the materials given to
achieve great range and accuracy.
II.
III.
Build: Construct your catapult and give it a great name.
Test and Modify: Here is when things get tough, testing and modifying.
You will need to do test launches for maximum range only at first. We will
be testing accuracy in about a week.
IV.
Improve: Identify how you can modify your catapult to improve its range
V.
Modify: Make the changes you identified and test again. Engineers do this
all the time; they test and modify their creations to make them better.
Materials:
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Cardboard shoe box (1 for each catapult and students will bring this in)
Rubber bands (4 for each catapult)
Popsicle sticks (2 for each catapult)
Masking tape (one 6-inch piece for each catapult)
Plastic spoon (1 for each catapult)
Rulers (1 per student group)
Scissors (1 per student group)
Marshmallows (2 per group)
Masking tape (for launching competition)
Object of your choice to serve as a target
Now it is competition time!!!
Each group will get three launches, only the best launch will count. The group
who sends their marshmallow the greatest distance will receive a one day homework
pass. This pass doesn’t excuses you from a home work it just means you can hand it
in one day late without penalty.
THE WINNER IS ______________________________
Let’s now take a look at the physics behind catapults.
a. In order to get the catapult to launch a marshmallow what must be done to the
catapult? ______________________________________________________
b. What type of energy does the catapult have the moment before releasing the
catapults arm launching the marshmallow?
__________________________________________________
c. What is the definition of elastic potential energy? _______________________
_____________________________________________________________
d. How does the catapult transfer its energy into marshmallow? ______________
_____________________________________________________________
e. What is the definition of a force? ___________________________________
f. The force from the catapult transfers the elastic potential energy possessed by
the catapult into the marshmallow as what form of energy? _______________
g. Why does the marshmallow have this type of energy? ____________________
h. What is the definition of kinetic energy? ______________________________
_____________________________________________________________
i. After the marshmallow leaves the catapult some of the kinetic energy was used
to elevate the marshmallow, make it go up. This means some of the kinetic
energy was converted into ____________________ energy. It becomes this
type of energy because the marshmallow has ____________________.
j. What is the definition of gravitational potential energy? __________________
_____________________________________________________________
k. A real catapult acts the same way. Energy is converted from one form to
another in accordance to the Law of Conservation of Energy which
states:
Energy cannot be created nor destroyed,
it can only be transferred or converted
The transfer of energy can be easily observed when it is mechanical energy
(elastic potential energy, kinetic energy or gravitational potential energy).
Eventually the projectile, rock or marshmallow, will come to rest on the ground
having no more mechanical energy.
l. The law of conservation of energy states that the energy can’t just go away, so,
where did the energy go? _________________________________________
_____________________________________________________________
m. Now it is time to take everything leaned about how about how a catapult uses
energy and put it into paragraph form. Using the following words explain how
a catapult obeys the law of conservation of energy by describing how the
energy is transferred from start to finish. BOX each word when it is used
 Force
 Elastic potential energy
 Kinetic energy
 Gravitational potential energy
 Heat
 Transfer or converted
 Law of conservation of energy
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 The next phase in our catapult testing is the accuracy phase. Before we can test
for accuracy though we need to figure out how to predict the range of our
catapult, to do this we need graphing.
 The teacher will now store all the catapults until the graphing activities are
complete. Only then will you have the ability to use graphing to predict your
catapults range.