Materials Needed:
- Ramp (plank)
- Several prototype cars
- Without motors
- Various axle and bearing components
- Approximately the same weight
Procedure: (see Figure 13)
- Mark a start line on the plank.
- Place the first car and let it roll down the ramp.
- Mark the location it rolled to.
- Repeat steps 2-3 3 times for each car or until the
car repeatable rolls to the same place.
- Repeat steps 2-4 for each car.
- Did the cars travel in straight lines?
- Which car went further?
- Try improving your chassis/wheel car with
different axles or bearings or lubricants
and see how they alter the final distance
the car travels.
Figure 13: Rolling resistance investigation setup
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Observations:
Using this roll down test you can find the bearing and wheel
configuration with the lowest rolling resistance (do not change
the aerodynamics [shape] of the car during this test because
that will also affect the results.) Finding the best combination
is an important step in building a fast car.
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