- #1
onecupoftea
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Homework Statement
A source of light emits a train of waves lasting 0.04 μs. The light has a wavelength of 600nm and the speed of light is 3×108ms-1. How many complete waves are sent out?
a)2.0×107
b)4.5×107
c)2.0×1010
d)4.5×1013
Homework Equations
f=v/wavelength (sorry, I couldn't find the wavelength symbol)
T=1/f
The Attempt at a Solution
Ok, this is what I tried:
f=v/wavelength
f=3×108/600×10-9
f=0.0005
T=1/f
T=1/0.0005
T=2000
then I did:
0.04×10-6/2000
=2×1010
Which was so close to one of the answers; frustrating! Could somebody please explain to me what to do? It's driving me crazy. I'm finding it hard to carry on with the rest of the assignment because I keep going back to that question and staring at it, willing my brain to work!