Marshmallow Catapult
Your science project is to build a marshmallow catapult. Your catapult must
contain at least one simple machine. Your catapult will be put to the test against
the other student’s in class. Your grade will be based on the rubric attached,
which relies heavily on a typed scientific lab report.
Materials you may use for your catapult must be everyday items. Some items
may include: paper cups, rubber bands, pencils, coffee stir sticks, paper clips,
milk cartons. What may not be included: legos, miniatures from a store, items
purchased that are already assembled as a catapult. If you have any concerns
regarding your materials, ask Mrs. Deal first.
You will construct your catapult at home. After it is constructed you will then
run tests on it to collect your data. You should use the large marshmallows, not
small or mini ones. We will also have a competition at school the day before
your lab report is due. Everyone will bring their catapult and we will fling
marshmallows toward a target.
Parts of your typewritten lab report:
Title: Should be a brief, concise statement about your experiment
Problem: Describes what you are trying to do
Hypothesis: Predicts your outcomes
Materials: Must include everything you used, should follow rubric
Procedures: This is so another person can replicate your experiment. Should be
very detailed
Data: Report all of your results in paragraph form with charts and graphs
supporting your data.
Conclusion: Did the results support or reject your hypothesis? Discuss why it
supported or why it did not.
Building A Structure : Marshmallow Catapult
Teacher Name: Mrs. Deal
Student Name:
________________________________________
4
3
2
1
Construction Materials
Appropriate
materials were
selected and
creatively modified
in ways that made
them even better.
Appropriate
materials were
selected and there
was an attempt at
creative
modification to
make them even
better.
Appropriate
materials were
selected.
Inappropriate
materials were
selected and
contributed to a
product that
performed poorly.
Function
Structure functions
extraordinarily well,
holding up under
atypical stresses.
Structure functions
well, holding up
under typical
stresses.
Structure functions
pretty well, but
deteriorates under
typical stresses.
Fatal flaws in
function with
complete failure
under typical
stresses.
Clear evidence of
troubleshooting,
troubleshooting,
testing, and
testing and
refinements based refinements.
on data or scientific
principles.
Some evidence of
troubleshooting,
testing and
refinements.
Little evidence of
troubleshooting,
testing or
refinement.
Problem
The purpose of the
lab or the question
to be answered
during the lab is
clearly identified
and stated.
The purpose of the
lab or the question
to be answered
during the lab is
identified, but is
stated in a
somewhat unclear
manner.
The purpose of the
lab or the question
to be answered
during the lab is
partially identified,
and is stated in a
somewhat unclear
manner.
The purpose of the
lab or the question
to be answered
during the lab is
erroneous or
irrelevant.
Experimental
Hypothesis
Hypothesized
relationship
between the
variables and the
predicted results is
clear and
reasonable based
on what has been
studied.
Hypothesized
relationship
between the
variables and the
predicted results is
reasonable based
on general
knowledge and
observations.
Hypothesized
relationship
between the
variables and the
predicted results
has been stated,
but appears to be
based on flawed
logic.
No hypothesis has
been stated.
Materials
All materials and
setup used in the
experiment are
clearly and
accurately
described.
Guidelines followed
for allowable
materials
Almost all materials
and the setup used
in the experiment
are clearly and
accurately
described.
Guidelines followed
for allowable
materials
Most of the
materials and the
setup used in the
experiment are
accurately
described. Most
guidelines followed
for allowable
materials
Many materials are
described
inaccurately OR are
not described at all.
No guidelines
followed for
allowable materials
CATEGORY
Modification/Testing Clear evidence of
Procedures
Procedures are
listed in clear steps.
Each step is
numbered and is a
complete sentence.
Procedures are
listed in a logical
order, but steps are
not numbered
and/or are not in
complete
sentences.
Procedures are
listed but are not in
a logical order or
are difficult to
follow.
Procedures do not
accurately list the
steps of the
experiment.
Data
Results described
accurately in
sentence form as
well as tables or
graphs. Repeated
at least 10 times.
Clear, accurate
diagrams are
included and make
the experiment
easier to
understand.
Diagrams are
labeled neatly and
accurately.
Results described
accurately in
sentence form as
well as tables or
graphs. Repeated
between 5-9 times.
Diagrams are
included and are
labeled neatly and
accurately.
Most results
described in
sentence form as
well as tables or
graphs. Repeated a
couple of times.
Diagrams are
included and are
labeled.
Experiment not
repeated. Needed
diagrams are
missing OR are
missing important
labels.
Conclusion
Conclusion includes
whether the
findings supported
the hypothesis,
possible sources of
error, and what was
learned from the
experiment.
Conclusion includes
whether the
findings supported
the hypothesis and
what was learned
from the
experiment.
Conclusion includes
what was learned
from the
experiment.
No conclusion was
included in the
report OR shows
little effort and
reflection.
You may use the references below as needed to help with writing your lab
report. Although we may have fewer steps than some of these, they offer
tremendous direction to assist in writing your lab report.
http://shs.westport.k12.ct.us/mjvl/science/labformat.htm#title
http://www.mrbigler.com/documents/report-style-guide.html
http://wwwbths.stjohns.k12.fl.us/teachers/gasht/marsci/Writing%20Laboratory%20Reports%
20for%20Marine%20Science.pdf
http://msjensen.cehd.umn.edu/1135/Worksheets/lab2.pdf
http://www.unc.edu/depts/wcweb/handouts/lab_report_complete.html
http://www.sau17.org/users/ehumehoward/PDFFiles/lab6.pdf
Sample Lab Report
(Title with NO NAME. Times New Roman font size 12. Double Spaced)
Balloon- Powered Racer
Introduction:
The purpose of this investigation was to design and build a car powered only by a deflating balloon which would
travel a specified distance and come to rest on a target. When a balloon deflates, the escaping air exerts a force on
the air to the rear of the balloon. According to Newton’s third law of motion, the air outside the balloon exerts a
force back on the balloon the same magnitude, but in the opposite direction, which causes the balloon to move
forward. This works because the balloon has a small mass. Newton’s second law of motion states that if a force is
exerted on a mass, it will cause the mass to accelerate in the direction of the force. However, if the mass is too large,
the force may not be strong enough to move it. Gravity and friction are two forces that oppose motion. (Explain how
gravity and friction affect the motion of objects and how if could affect the performance of your car)
Because balloons have such a small mass, they accelerate quickly by deflating. Attaching the balloon to a car
increases the mass that the force of the deflating balloon has to move. If the car has too much mass, the balloon will
not move it. The balloon and car had to have a mass small enough to be accelerated by the force of a deflating
balloon. (Explain your design, and why you chose the materials you did. Also explain how you overcame the friction
in the wheels, what you made it out of to reduce mass, etc, and got the car to move using only a balloon)
In this investigation, a line represented the starting line. Once the balloon-powered car crossed the starting line it
was not allowed to be touched. The car then had to travel a distance of (write in the distance) before it reached the
beginning of the scoring zone. At the other end of the scoring zone was the target line. The total scoring zone was
(write in the distance). The balloon racers were required to come to rest inside the (distance) scoring zone in order to
be qualified. The car that came closest to the target line without going over won the competition. (See diagram
below) (Draw a diagram of the whole experimental setup)
Methods and Materials:
The following materials were required to perform this investigation:
(List all of your materials including everything you used to build your car and everything we used in class to
perform the competition)
Experimental procedure:
Construct the balloon powered car as follows: (Explain how to build your car and how it works. Include pictures
and diagrams of it)
To perform the competition:
1. Place one balloon powered car at the starting line with the balloon inflated and the car prepared to go, then
allow the air from the deflating balloon to accelerate the car into the testing area until it comes to rest.
2. If it comes to rest outside the scoring zone, it is disqualified. If it comes to rest inside the scoring zone,
measure the distance from the target line to the point of the car closest to the line and record.
3. Repeat with the next car until all cars have had a chance to compete. The closest to the target line without
going over wins the competition.
Results:
(Write out the results of all of the qualifying cars in a sentence or 2)
(Make a data table with all of the qualifying cars and their distances from the target line)
(Make a bar graph based on the table. Include title and axis labels)
Conclusion:
The purpose of this investigation was to design and build a car powered only by a deflating balloon which
was to come to rest on a specified target. This was done by (give a brief explanation of experimental design and
scoring rules) The winning car, (Name of car) had a distance of (distance) from the target line. This design was so
successful because (give a description of the car’s design and why you feel it worked so well. Pictures help.) The
second place car reached a distance of (distance) from the target line (give a description of the car’s design and why
you feel it worked so well. Pictures help. Repeat this format for all qualifying cars) (If your car landed in the scoring
zone, just mention it when you list it above; “The second place car, which was described in the methods and
materials section above, reached a distance of…) (If your car did not land in the scoring zone: “The car described
in the methods and materials section above did not come to rest in the scoring zone. It reached a distance of…)
(explain why your car did not qualify, what you would change in your design (not copying someone else's) and why.
Explain anything you were surprised by (such as the balloon losing elasticity), or anything unexpected during this
investigation.) (Finally, come up with a new experiment based on this one. Example: ideas about a balloon-powered
distance or speed contest, or a balloon-powered flying vehicle contest, or whatever else you can think of)
***REMEMBER: All pictures (including graphs) MUST have a reference to them in the text! (Example: "See
picture 1, page 3" or "See graph 1, page 7")