Having fun with a cordless mouse

Abstract

A cordless mouse with an added reed switch is used as a wireless data logger to record every time the wheel of a trolley completes a revolution. The limitations of the system in terms of maximum clicking rate and spatial resolution are considered and data obtained from the descent of a trolley down a ramp at various different angles is analysed in different ways. The data is analysed to obtain initial accelerations (down the ramp) and subsequent decelerations (on the flat), as well as maximum velocities, and these results are used to compare the actual performance of the trolley (with friction) with the theoretical expectation. An agreement of better than 2% on the value of gravity is obtained. Encouraging agreement on frictional forces (and accelerations) is also obtained by considering the maximum kinetic energies reached at the bottom of the ramp. This paper includes the free provision of custom software to record the time history of the clicking of a mouse.