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### Quiz 2 Question #6

Posted: Wed May 09, 2018 3:21 pm
Hi so I was looking at the post that was similar to this one. But I still dont know how to convert my answers to nanometers. I got stuck on the second part.

The question is:
Radio stations use radio waves to send sounds through the air. Radio waves have a frequency of about 7 X10^6 Hz. Determine the energy, in J, and the wavelength in nm, of a radio wave.

So of course E=hv
E=(6.626x10^-34 j.s) x (7x10^6 Hz)
E= 4.64 x 10^-27 J

However i get stuck here.

Lambda =c/v

Lamba = 2.998 x 10^8 m.s / 7x10^6 Hz
Lamda = 4.28 x 10^13 m.

Please help me in converting this to nanometers. Thank you.

### Re: Quiz 2 Question #6

Posted: Wed May 09, 2018 4:04 pm
I'm not too sure how you got 4.28x10^13m, when entering this into a calculator I got 42.9m. However, in order to turn meters into nm, all you would have to do is divide it by 10^-9. Essentially, 42.9m x [1nm/(10^-9m)] = 4.29x10^10 nm. I hope this helps.

### Re: Quiz 2 Question #6

Posted: Wed May 09, 2018 4:41 pm
Messed up on the decimal is what it was. Thank you!