Answer:
When a flashing light source approaches you, the frequency of light increases while the speed of light remains constant.
The phenomenon of an approaching light source causing an increase in frequency is known as the Doppler effect. It occurs because the motion of the source affects the wavelength of the emitted light. As the source moves closer to an observer, the waves are compressed, resulting in a higher frequency. Conversely, when the source moves away, the waves are stretched, leading to a lower frequency.