Question

1. a wave has a wavelength of 20 m, what is the frequency and energy of the wave? clear all no answer can be determined from the information given 150000/9.939x10^-29 15000000/9.939x10^-17 150/9.939x10^-12

Explanation:

Step1: Recall wave - speed formula

The speed of light $c = 3\times10^{8}\ m/s$ and the wave - speed formula is $c=\lambda
u$, where $\lambda$ is the wavelength and $
u$ is the frequency. Given $\lambda = 20\ m$, we can solve for $
u$.
$
u=\frac{c}{\lambda}=\frac{3\times10^{8}\ m/s}{20\ m}=1.5\times10^{7}\ Hz = 15000000\ Hz$

Step2: Recall energy formula

The energy of a photon is given by $E = h
u$, where $h = 6.626\times10^{-34}\ J\cdot s$ is Planck's constant. Substitute $
u = 1.5\times10^{7}\ Hz$ into the formula.
$E=h
u=(6.626\times10^{-34}\ J\cdot s)\times(1.5\times10^{7}\ Hz)=9.939\times10^{-27}\ J$

Answer:

15000000/9.939x10⁻²⁷