Here's why:
* Frequency is a property of the light source: The frequency of light is determined by the source that emits it. For example, a red laser emits light with a specific frequency that corresponds to the color red.
* Refraction changes the speed and wavelength: When light passes from one medium to another (like from air to water), its speed changes. This change in speed also affects the wavelength of the light (the distance between wave crests).
* Frequency remains constant: The relationship between the speed of light (v), wavelength (λ), and frequency (f) is given by the equation: v = fλ. Since the speed changes during refraction, and the frequency remains constant, the wavelength must adjust accordingly.
In summary: Refraction changes the speed and wavelength of light, but the frequency, which is a fundamental property of the light itself, remains unchanged.
