# Angular Velocity of Pendulum

Objective

To study the nature of oscillations of a pendulum. An angle encoder is required for measuring the angular displacement as a function of time. But using a DC motor as a sensor, we can measure the angular velocity as a function of time.begin_inset Separator latexparend_inset

Procedure

- Attach some sort of rigid pendulum to the axis of the motor.

- Connect the motor between A3 and GND

- Connect resistor from Rg to Ground

- Oscillate the pendulum and START digitizing

Discussion

The observed waveform is shown in figure. Fitting it with equation , using Grace gave an angular frequency of .

The pendulum should be made with a heavy bob and a light weight rod connecting it to the axis of the motor. In this case, the DC motor acts like a generator and the voltage is proportional to the instantaneous angular velocity.