# A Beam of Red Light: Understanding Wavelength and Frequency

## The Relationship Between Wavelength and Frequency

**Wavelength** and **frequency** are two fundamental properties of a wave. In the case of light waves, which are part of the electromagnetic spectrum, the wavelength refers to the distance between two consecutive peaks of the wave, while the frequency represents the number of oscillations per unit of time. These two properties are closely related to each other through the speed of light, which is a constant in a vacuum.

When light travels through a medium, its speed decreases, but its frequency remains constant. This means that as the wavelength changes, the frequency also changes inversely. In other words, if the wavelength increases, the frequency decreases, and vice versa. This relationship is described by the equation:

**c = λν**

where **c** is the speed of light, **λ** is the wavelength, and **ν** is the frequency. By knowing the wavelength of a light wave, we can calculate its frequency using this equation.

## Calculating Frequency from Wavelength

Given that the red light has a wavelength of 713 nm, we can calculate its frequency by rearranging the equation above:

Frequency = Speed of Light / Wavelength

Frequency = 3.00 x 10^8 m/s / 713 x 10^-9 m

Frequency ≈ 4.21 x 10^14 Hz

Therefore, the frequency of the red light beam is approximately 4.21 x 10^14 hertz.

## Conclusion

Understanding the relationship between wavelength and frequency is essential in the study of light and other electromagnetic waves. By knowing the wavelength of a light wave, we can easily calculate its frequency using the speed of light constant. This knowledge is crucial in various fields such as optics, telecommunications, and astronomy.

A beam of red light has a wavelength of 713 nm. What is the frequency? The frequency of the red light beam is approximately 4.21 x 10^14 hertz.