Just one harmonic motion problem

[mustang]

Problem 17.
The speed of all elctromagnetic waves in empty space is 3*10^8 m/s.
What is the wavelength of X rays emitted at 3.2*10^12 MHz? Answer in m.
This is what I have done;
wavespeed=frequence times wavelength
3*10^8/3.2*10^12 = 9.375 * 10 ^-5 m
I got this answer for the problem but when I submitted the answer it was wrong, what did I do wrong?

 

[Doc Al]

The frequency was given in MHz; you need to convert to Hz. 1 MHz = 10^6 Hz.

 

[mustang]

Reply

Would it then be 3.2*10^12MHz * 10^6Hz=3.2*10^19 Hz

 

[himanshu121]

Originally posted by mustang
Would it then be 3.2*10^12MHz * 10^6Hz=3.2*10^19 Hz

12 + 6 = ?

 

[mustang]

So himanshu121 it would really be 3.2*18. Since you pointed out 12+6=18?

 

[himanshu121]

Dear it is 3.2 * 10¹⁸ Hz now apply the formula u will get it

 

[mustang]

Reply

So by dividing 3*10^8 by 3.2*10^18 = 9.375*10^-11 is the answer?

 

[Doc Al]

Originally posted by mustang
So by dividing 3*10^8 by 3.2*10^18 = 9.375*10^-11 is the answer?

Yep. Your original answer was off by a million, since you used the wrong units for frequency.