Physics
posted by Jon on .
1)An electromagnetic wave is produced by:
an accelerating charged particle or changing magnetic fields.
2)Find the period of an electromagnetic wave of wavelength 2.20 x 10^2 m.
3.00 x 10^8 * 2.20 x 10^2
= 6.60 x 10^6 s

2) 1/period*wavelength=speedoflight
period=wavelength/speedoflight.
Also, think about your answer. A million seconds for one period? Goodness. 
2)I don't really understand 1/period*wavelength. I can't multiply period times wavelength if I don't know the period. but I did get a different answer. my book doesnt show me how to find the period I just used wavelengthfrequency relationship for a wave equation to find the frequency
2.20 x 10^2/3.00 x 10^8
= 7.33 x 10^11
these are my choices by the way:
A)1.36 x 10^10
B)4.54 x 10^1
C)7.33 x 10^11
D)6.60 x 10^6 
frequency = (speed of light)/(wavelength)
= 3*10^8 m/s/(2.2*10^2 m)
Looks like (A) to me.
All I did was rearrange the equation BobPursley gave you.
If you would label your calculations with dimensions, and write down your equations, it would be easier for you to find your own errors. Once again, it seems you are just plugging in numbers at random. 
thank you but no I did not 3.00 x 10^8 is the speed of light constant I got from my book not out of my head that's what I use to find the wavelength

the answer was C