Determining the Acceleration Due to Gravity and Friction Using the Ticker Tape Timer Method

Measuring the acceleration due to gravity g is a part of most introductory physics classes. A standard method to do so is by using a ticker tape timer. However, frictional forces are usually not included in the analysis even though friction leads to an acceleration significantly smaller than g. In this note, we show how to obtain accurate values of both the gravitational acceleration and the friction force by making measurements with different masses. We also propose a way to organize the laboratory procedure to make the multiple measurements needed, to be more collaborative, and to require students to think more carefully about their results. Students are also exposed to the importance of accounting for the variability in measurements.