Rubber Band Car

Physics Olympics 2015 — Rubber Band Car Event

Objective: build a car that is powered by three Whole Foods green rubber bands.


The car:

1) Powered by three Whole Foods green rubber bands. If coaches or students have any questions on what this means, email the event runner.

2) The car may use a propeller or not, but the kinetic energy of the car may only derive from the transformation of the  stored elastic potential energy of (at most) the three green Whole Foods rubber bands.

3) No part of the car may be store-bought except wheels, axles, propellers, and of course the rubber bands. The chassis, for example, may not come from a store-bought (i.e., previously manufactured) car.

* 4) The team supplies rubber bands for the actual event. The bands must be easily removable from the car in case the judge wants to do an inspection.


The event:

The car attempts to reach the finish line as quickly

and as close to the target as possible.


The car’s trial ends when the first of these events occurs:

  • The car crosses the finish line.
  • Any wheel crosses the sideline.
  • 30 seconds elapse.


There are two tiers for scoring:

Tier 1 —  Cars that cross the finish line before the trial ends.

Tier 2 —  Cars that don’t.

Any car in Tier 1 automatically beats a car in Tier 2, regardless of which car was faster or more accurate.


Tier 1

If a car passes the finish line in C, score = (avg. speed)*1.0.

If a car passes the finish line in B, score = (avg. speed)*1.1.

If a car passes the finish line in A, score = (avg. speed)*1.2.


Avg. speed =  (forward distance traveled) / time


A car is scored as finishing in the highest value zone if one wheel crosses the finish line in that zone.


Tier 2

Score = forward distance traveled at point of leaving track.