## Problem 1.4

$c=\lambda v$

Tim Foster 2A
Posts: 73
Joined: Fri Sep 29, 2017 7:07 am

### Problem 1.4

The problem asks which statement is true
A) x-rays travel faster than infrared radiation
B) the wavelength of visible radiation decreases as its color changes from blue to green
C) the frequency of infrared radiation is half that of radio waves
D) the frequency of infrared radiation is twice that of radio waves

I don't see a correct answer here, where am I going wrong?

Nancy Dinh 2J
Posts: 59
Joined: Fri Sep 29, 2017 7:07 am

### Re: Problem 1.4

I can't see a correct answer either. Maybe the book is trying to pull one over us, and there is none???

Amelia Georgius 1K
Posts: 25
Joined: Fri Sep 29, 2017 7:05 am
Been upvoted: 1 time

### Re: Problem 1.4

I'm confused with this problem as well because A. all waves travel at the speed of light, which is a constant, B. The wavelength of visible light increases as it changes from blue to green (but the frequency does decrease), and when you calculate the frequency of infrared radiation and radio waves, neither of them are double or half of each other.

Emily Oren 3C
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

### Re: Problem 1.4

I'm pretty sure that this is a trick question and none of the answers are correct (but I think the wording is open to the possibility of there being no correct answer)
A) This isn't true because all EM radiation travels at a constant speed in a vacuum and they did not say that there was a medium
B) From blue to green the wavelength increases not decreases
C/D) infrared light with a wavelength of 1.0*10^3 nm has a frequency of 3.0*10^14 Hz which is neither half of or twice 3.0*10^11 Hz which is the frequency of a radio wave with a wavelength of 1.0*10^6 nm