Gummy Bear Launching

Question:

What is the most effective ruler for launching Gummy Bears?

Background:

One day, in Mr. Rick's science class, a student was supposed to be making graphs, but instead the student was eating Gummy Bears (GB) when Mr. Rick wasn't looking. At some point the student realized that by placing one end of the ruler on the edge of the table with the other end hanging off the edge, the student could make a "spring board" that could launch the GB into the air and it would stick to the ceiling. The plastic ruler the student had worked OK, but the GBs dropped off the ceiling within 3 minutes. Looking around the room, the student traded some GBs for a wooden ruler thinking it would stick the GBs better. Before the student could complete the experiment, a GB dropped off the ceiling onto Mr. Rick's bald head. As punishment, Mr. Rick made the student do a formal lab experiment. This is the lab report for that experiment.

Prediction/Hypothesis:

If different rulers are used for the Gummy Bear Launcher then the metal ruler will stick the Gummy Bear to the ceiling the longest because the metal ruler is springier.

Materials:

Procedure:

  1. Find a table below a section of ceiling without lights or other obstructions. The ceiling will be the usual acoustic panel found in schools. (controlled variable)
  2. Measure and record the distance from the table top to the ceiling. (controlled variable)
  3. Place the wooden ruler such that 10cm (~4 inches) is on the table surface. The wooden ruler will be our control group. (controlled variable) (control group)
  4. Have a helper press down on that end of the ruler so that it can not move at all. (controlled variable)
  5. Place a GB 2.5cm (~1 inch) from the end of the ruler. (controlled variable)
  6. Depress the end of the ruler 7cm (~3 inch) from the level of the table top. Use one of the other rulers to measure this. (controlled variable) (validity measure)
  7. Quickly let go of the ruler end.
  8. Measure and record the length of time the GB sticks to the ceiling. If the GB doesn't stick record "NS" (no stick) in the data table. (responding variable)
  9. Repeat steps 3 through 8 for the next two trials. (repeated trials)
  10. Repeats steps 3 through 9 for each of the other two rulers. (manipulated variable)
  11. Calculate and record the average GB sticking time.

Data/Analysis:

Distance from table to ceiling = 210cm


Ruler Trial 1 (secs) Trial 2 (secs) Trial 3 (secs) Average (secs)
Wood 1 2 NS 1.5
Plastic 1 NS NS 1
Metal 2 2 1 2.5

Conclusion:

The hypothesis was "If different rulers are used for the Gummy Bear Launcher then the metal ruler will stick the Gummy Bear to the ceiling the longest because the metal ruler is springier." This hypothesis was supported. The average Gummy Bear sticking time for the wooden ruler (control group) was 1.5 seconds. The average sticking time for the plastic ruler 1 sec and for the metal ruler 2.5 seconds. The Gummy Bears launched with the metal ruler stuck to the ceiling a full second longer than the next closest ruler, supporting the hypothesis.

Gummy Bears not sticking or missing the ceiling were a problem with this experiment. In the future depressing the rulers more or getting closer to the ceiling might work better. Having different brands of the rulers would give more complete results.