SCN 440 RAT TRAP CAR CONTEST
OBJECTIVE:
Build a vehicle powered solely by the energy of one standard-sized rat trap that
will travel the greatest linear distance, but a minimum distance of 4.0 m.
By definition, a vehicle is a device with wheels or runners used to carry
something, (e.g., car, bus, bicycle or sled). Therefore, launching a ball, (e.g.,
marble) from the rat trap will be ruled illegal.
TEAM:
Teams must consist of 2-3 students. Each student must participate in both the
vehicle design as well as the reflection paper. Teams are expected to be
creative and promote their vehicle in some way on race day (i.e. t-shirts, food,
etc.)
RULES:
1. The device must be powered by a single Victor brand rat trap. Other brands
may be used if permitted.
a. The rat trap may be physically altered if you wish.
2. The device cannot have any additional potential or kinetic energy at the start
other than what can be stored in the rat trap's spring itself. (e.g. you cannot
push start your vehicle).
3. The spring cannot be wound more than its normal travel distance or 180
degrees.
4. Vehicles must be self-starting. Vehicles may not receive a push in the
forward direction or side direction.
5. The vehicle must steer itself. Measurements of distance will not measure the
total distance traveled only the displacement distance.
6. Distance will be measured from the front of the tape at the starting line to the
point of the vehicle that was closest to the start line at the time of release.
7. The instructor has the final decision as to the appropriateness of any
additional items that might be used in the construction of the racer.
THE RACE TRACK:
The competition will be held on a smooth level floor (i.e. a gymnasium or a noncarpeted hallway).
RACE DAY:
Each team will be given three attempts. Only the value of greatest linear
distance will be used for scoring purposes. Students may not touch or interfere
with the vehicle once the lever has been tripped.
AWARDS:
Awards will be given out for creativity, mechanical design, and distance.
DESIGN HELP:
1. http://users.bigpond.net.au/mechtoys/mouse.html
2. www.docfizzix.com/design-help/free-links.shtml
REFLECTION REPORT:
Chose 7 of the following questions to answer in your Reflection Report:
1. What are the two types of friction that affect the performance of your vehicle?
2. What problems related to friction did you encounter and how did you solve
them?
3. What factors did you take into account to decide the number of wheels you
chose in your design?
4. What kind of wheels did you use in each axle? What is the effect of using
large or small wheels?
5. Explain how Newton's first, second and third laws apply to the performance of
your vehicle.
6. Discuss the effect of the length of the lever arm in the pulling force of your
vehicle.
7. How is the balance of a wheel, around its center, related to the vehicle’s
performance?
8. How does the distribution of weight of the vehicle affect the traction of the
wheels?
9. Discuss the major problems encountered in the performance of your vehicle
and what did you do to solve them.
NOTE: REPORTS ARE DUE ON RACE DAY!!!
SCN 440 RAT TRAP CAR CONTEST
SCORING SHEET
TEAM MEMBERS:
___________________
___________________
___________________
MECHANICAL DESIGN:
Criteria
Possible
Points
All Design Specifications Met
5
Received
Points
Quality of Construction
10 pts. = excellent application of design, construction and assembly.
8 pts. = very good construction, assembly, and attention to detail.
6 pts. = good construction and assembly and some attention to detail.
4 pts. = fair construction and assembly. Minimal attention to detail.
0 pts. = last minute project. No attention to detail.
10
TOTAL POINTS: ________ / 15
DISTANCE:
Beyond 10.0 m, a team will receive one point of extra credit for every additional
meter that its vehicle travels.
Criteria
Possible
Points
Received
Points
Distance Vehicle Traveled
16 points = Final displacement is 10 m
14 points = Final displacement is 9 m
12 points = Final displacement is 8 m
10 points = Final displacement is 7 m
8 points = Final displacement is 6 m
6 points = Final displacement is 5 m
4 points = Final displacement is 4 m
0 points = Final displacement is less than 4 m
Additional Distance Traveled by Vehicle
16
NA
TOTAL POINTS: ________ / 16
CREATIVITY:
Criteria
Possible
Points
Race Day Vehicle Promotion
5
Personalization of Vehicle
5
Uniqueness of Design
5
Received
Points
TOTAL POINTS: ________ / 15
REFLECTION REPORT:
Criteria
Possible
Points
Question #1
2
Question #2
2
Question #3
2
Question #4
2
Question #5
2
Question #6
2
Question #7
2
Received
Points
TOTAL POINTS: ________ / 14
TOTAL PROJECT POINTS: ________ / 60