We present four experiments (spring, pendulum, free fall, and parabolic throw) for measuring the acceleration due to gravity g, using a computer sound card. In each case, a device is connected to the audio input and an audio editing software [1] is used for recording the electric signal generated by the device. This method allows time measurements with an accuracy of about 10-4 s.
- In the mass-spring system [2], the signal comes from the electric current generated in a coil by a magnet attached to the mass hanger.
- In the pendulum case [3], the signal comes from an optocoupler that detects the motion of the thread.
- In the free fall case [4], the signal comes from the electric current generated by the passage of a small magnet through three coils located at different heights in a vertical methacrylate tube.
- In the parabolic throw case [5], the signal comes from the sound generated by a steel ball, stroked by another ball, from a known height.
These experiments are enriched with other physical phenomena that contribute to learning with the support of new technologies.