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The
Slingshot Project
A Freshman Engineering
Design Project
Developed by Dr. Ron Roedel, Arizona State University
Instructions to
Students
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1. |
Project
Description
Each
team will be given a plastic water balloon slingshot
that has a “basket” that is the perfect size to hold a
rubber squash ball. You are to design a device that
will securely hold, accurately aim, and reproducibly
release the squash ball. You will be shown a cart and
given this cart’s dimensions so that you can design your
device so that it can be mounted on top of the cart.
Each team is to decide and angle with respect to the
horizontal that the device would hold the slingshot at.
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2. |
Design
Constraints
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The total cost of any additional parts, except the
dimensional lumber, is not to exceed $5.35 (receipts
had to be provided).
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3. |
Designing
the Device
First,
you will brainstorm ideas in your team for a possible
design. Once a preliminary design is agreed upon, your
team is to turn in a drawing that includes dimensions of
all the wood that is needed to construct the launch
device. The dimensional drawings will then be handed
over to the wood shop and the wood each team needs will
be cut and given back to the team. When your team
receives its wood, your team will construct the device.
The teams will be provided any tools and hardware that
is needed to assemble the devices. If your team has any
special equipment that is needed but not provided, your
team will have to purchase that equipment, so long as it
does not exceed the cost of $5.35.
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4. |
Ball
Trajectory Data Gathering
After
the launch device is constructed, the teams will have to
obtain data on the trajectory of the ball being launched
as a function of the length of the pull of the elastic
cord. To do this, the teams will gather in a gym to
record videotapes of their squash balls being launched.
The teams are to decide on three pull lengths to use so
that they can obtain the ball trajectory as a function
of the pull length. Each of the three launches is
videotaped so that the teams can digitize the video and
then determine a function from this data. Once the
teams have a function determined, they are ready for the
launch date.
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5. |
Launch Day
Information
On the
launch day, each team is given the horizontal and
vertical distance at which the .35m by .35m target will
be placed. The teams then have to determine how far they
will pull their cord back so that the slingshot will
launch the squash ball through the target. If the team
successfully shoots the ball through the target, the
team has demonstrated that their device and function
have worked properly. If the team fails to shoot their
ball through the target, they have to explain why their
device did not successfully launch the ball through the
target. Also, they have to explain how they would
improve the device so that it could successfully launch
the ball through the target. |
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6. |
Designing
Notebooks
Each
team is to keep a “design notebook” that documents the
design process that the team used. The notebook is also
to contain a succinct report that includes the final
outcome of the project as well as the final artifact and
a description of the project.
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Lesson
| Instruction
to Students
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