Chapter 7, Problem 7.1P

Interpretation Introduction

Interpretation:

The frequency of the green light emitted from a laser is to be calculated.

Concept introduction:

The frequency of light is the division of speed of light to the wavelength of light. The unit of frequency is ${\text{sec}}^{-1}$. The expression of frequency is, $\upsilon =\frac{c}{\lambda }$

To determine:

The frequency of the green light emitted from a laser.

Answer to Problem 7.1P

Solution:

The frequency of the green light emitted from a laser is $5.83\times {10}^{14}{\sec }^{-1}$.

Explanation of Solution

Given information:

The wavelength of the green light emitted from a laser is $515\text{nm}$.

The speed of light is $3\times {10}^8\text{m/sec}$.
The wavelength of light is $515\text{nm}$.
The conversion of $\text{nm}$ to $\text{m}$ as,
   $1\text{nm}={\text{10}}^{-9}\text{m}$.
Therefore,
   $\begin{array}{c}515\text{nm}=\text{515}\times {10}^{-9}\text{m}\\ =\text{5}\text{.15}\times {10}^{-7}\text{m}\end{array}$

The frequency of light is calculated by the formula,
   $\upsilon =\frac{c}{\lambda }$

Where,

• $\upsilon$ is the frequency of light.
• $\lambda$ is the wavelength of light.
• $c$ is the speed of light.

Substitute the values of the speed of light and the wavelength of light in the above formula as,
   $\begin{array}{c}\upsilon \text{of}\text{green}\text{light}=\frac{c}{\lambda }\\ =\frac{3\times {10}^8\text{m/sec}}{\text{5}\text{.15}\times {10}^{-7}\text{m}}\\ =5.83\times {10}^{14}{\sec }^{-1}\end{array}$.

Therefore, the frequency of the green light emitted from a laser is $5.83\times {10}^{14}{\sec }^{-1}$.

Conclusion

The frequency of the green light emitted from a laser is $5.83\times {10}^{14}{\sec }^{-1}$.