## 1A.7 Seventh edition

$c=\lambda v$

Karolina herrera1F
Posts: 33
Joined: Sat Feb 02, 2019 12:15 am

### 1A.7 Seventh edition

For this question it it states to find the frequency of violent light when it is 7.1x10^14 Hz it asks for the wavelength. I know that you would put the 7.1x10^14 Hz on the bottom, but I do not know what to put on. the top and why.

Posts: 36
Joined: Mon Jun 17, 2019 7:23 am

### Re: 1A.7 Seventh edition

In the question we are given frequency (v) and we need to find wavelength (λ).

We know that frequency and wavelength are related:c = λ ν

But in this problem we only know frequency (v) and c (the speed of light):

We rewrite the equation solving for wavelength:

c = λ ν (divide both sides by v): c/ν = λ => λ = c/ν (so starting with the equation we know we solve for λ, and get the speed of light(c) divided by the given frequency (v):

λ = (2.998 x10^8 m.s^-1)/(7.1x10^14 s^-1) = 4.2 x 10^-7 m = 420 nm