When a spring mass system is driven by an external sinusoidal force, the amplitude of oscillation is given by-

$$A(\omega) = \frac{F}{m\sqrt{(\omega^{2} - \omega_{0}^{2})^{2} + \omega^{2}\gamma^{2}}}$$

Where

\(F\) - amplitude of driving force

\(m\) - mass of the oscillator

\(\omega_{0}\) - natural frequency of the oscillator

\(\gamma\) - Damping constant

\(\omega\) - Frequency of driving force

When the frequency of the external driving force is close to the natural frequency of the oscillator, it has a maximum amplitude. This phenomenon is referred to as resonance and the frequency at which this occurs is known as resonance frequency of the oscillator.

Change the frequency of the external force and measure the amplitude of the oscillatory motion.