Question

the green light emitted by a stoplight has a wavelength of 517 nm. what is the frequency, in s⁻¹, of this photon? (c = 3.00 × 10⁸ m/s). answer: hz

Explanation:

Step1: Convert wavelength to meters

Convert 517 nm to m. Since 1 nm = 10^{-9} m, so $\lambda=517\times10^{-9}\text{ m}$.

Step2: Use the speed - wavelength - frequency formula

The formula is $c = \lambda
u$, where $c$ is the speed of light, $\lambda$ is the wavelength and $
u$ is the frequency. Rearranging for $
u$, we get $
u=\frac{c}{\lambda}$. Substitute $c = 3.00\times 10^{8}\text{ m/s}$ and $\lambda=517\times10^{-9}\text{ m}$ into the formula: $
u=\frac{3.00\times 10^{8}}{517\times10^{-9}}\text{ s}^{-1}$.

Step3: Calculate the frequency

$
u=\frac{3.00\times 10^{8}}{517\times10^{-9}}=\frac{3.00\times 10^{8}}{5.17\times 10^{-7}}\approx5.80\times 10^{14}\text{ Hz}$

Answer:

$5.80\times 10^{14}$