Here's why:
* Wave Speed, Wavelength, and Frequency: The speed of a wave (v) is related to its wavelength (λ) and frequency (f) by the following equation:
v = λf
* Constant Speed: For a given medium, the speed of a wave is usually constant. This means that if the wavelength increases, the frequency must decrease to keep the speed constant.
Examples:
* Light: The speed of light in a vacuum is constant. Red light has a longer wavelength than blue light, but both travel at the same speed.
* Sound: The speed of sound in air is also roughly constant. Lower-pitched sounds have longer wavelengths than higher-pitched sounds, but they travel at the same speed.
Exceptions:
There are some exceptions to this rule, where the speed of a wave can change with wavelength. For example:
* Dispersion: In some materials, like a prism, light waves of different wavelengths travel at slightly different speeds, causing the light to separate into its component colors (a rainbow effect).
In Summary:
Generally speaking, the speed of a wave is determined by the medium it travels through and does not change with its wavelength. If wavelength increases, frequency decreases to maintain a constant speed.
