In this experiment designed for use with PASCO Capstone software, students explore the dependence of the period of a simple pendulum on the amplitude of the oscillation. Also, the displacement, velocity and acceleration for large amplitude are plotted versus time to show the difference from the sinusoidal motion of low amplitude oscillations.
A rigid pendulum consists of a 35 cm long lightweight (28 g) aluminum tube with a 75 g mass on each end. The center of the tube is mounted on a Rotary Motion Sensor. One of the masses is slightly closer to the center than the other mass, so the pendulum will oscillate slowly. Students will have time to view the motion of the pendulum while also watching the real-time graph of displacement, velocity and acceleration versus time.
The period is measured as a function of the amplitude of the pendulum and compared to theory.
Using PASCO Capstone, the period function can be plotted versus the amplitude in real-time as the pendulum's oscillation damps out. The pendulum is initially displaced almost 180 degrees and then, as the amplitude decreases because of friction, the period is automatically recorded as a function of amplitude.
Graphs of angular displacement, velocity, and acceleration versus time are displayed for a pendulum oscillating with large amplitude.