Describe how the Doppler effect works.

The Doppler effect is a phenomenon that occurs due to the relative motion between the source of waves and the observer, causing a change in frequency and wavelength of the waves experienced by the stationary observer. When the source approaches the observer, the waves are compressed, increasing the frequency and decreasing the wavelength. Conversely, when the source moves away from the observer, the waves are stretched out, decreasing the frequency and increasing the wavelength. The Doppler effect formula for sound is given by \(f'=f\frac{v \pm v_o}{v \pm v_s}\), where \(f'\) is the observed frequency, \(f\) is the source frequency, \(v\) is the speed of sound in the medium, \(v_o\) is the observer's velocity, and \(v_s\) is the source's velocity. Examples of the Doppler effect can be found in everyday situations, medical imaging, and astronomy.