Students use a motion detector (CBR) and pendulum (fishing float) to collect data for the motion of a pendulum. The quality of the data never ceases to amaze students and teachers. Students align practical knowledge, logic and familiarity with the various parameters to transform a basic trigonometric function into a model for a pendulum.

Identify contexts suitable for modelling by trigonometric functions and use them to solve practical problems.

Period, amplitude, translation, dilation, parameter

Students use a CBR motion detector to measure the motion of a basic pendulum. Practical measurements and numerical data support the identification of the parameters in trigonometric function used to model the data. The phenomenal accuracy of the data and associated function encourages students to fine-tune their parameters to improve their model, constantly rehearsing the associated transformations supported with visual feedback and practical alignment making this a truly memorable mathematics activity.