Inclined Plane Puzzle

Challenge: To design and conduct a lab to answer the question: Is there a relationship between mass of an object and its acceleration down a slope?

Parameters: You are entirely responsible for the wording of the hypothesis, design of the apparatus, data collection, data representation, data analysis, and modelling of the physics involved. You must either support or refute the hypothesis with your data, and suggest further experiments that could provide you with a more comprehensive/correct model of the physics involved.

Scoring: Your score will be based on the quality of your hypothesis, procedure, data, graph(s), data analysis, and uncertainty analysis. Also whether or not you interpret your results correctly, and make reasonable suggestions for further experiments. There are no marks for your hypothesis being “right” or “wrong”.

Physics: If the surfaces in contact don’t change, and the angle of the plane does not change, one can show that theoretically the mass should not make a difference. If that is not supported by data, the explanation must involve an addition to your model.

Extensions: Uncertainty in measurements can be reduced by careful procedure, and multiple measurements can produce averages that have less uncertainty. Calculations with those measurements will give answers that are also uncertain. (propagation of uncertainty was a topic in grade 11) Uncertainty in your results should be part of your data analysis and also influence your decision to accept or reject your hypothesis.

Help/Hints: Video analysis is likely the best way to get data. Using at least 8 different masses would provide enough data to make a graph. Keeping the other variables constant will be an extremely important part of the process. For example, if your inclined plane slips a bit half-way through data collection you might be in trouble!

Quiz Topics: Measurement, Data analysis, Graphing, Uncertainty, Scientific Method

Online Text: 1.2, 1.3