- #1
sgoeke
- 14
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Homework Statement
Determine the amount of energy carried in 1 m of a 3.5 mW He-Ne laser beam if the cross-sectional area of the beam is 5x10^-6 m^2.
Homework Equations
J/s = Watt
The Attempt at a Solution
I converted the mW to W. I feel like I should put .0035W over 5x10^-6 m^2 to get intensity. But I don't know where intensity comes into this problem or where the other 1 m comes in.