A laser emits light at a wavelength of 632.8nm. The laser beams power is 1.0mW. Find the number of wave crests per second passing through nay point in the beam.(adsbygoogle = window.adsbygoogle || []).push({});

so f = [tex] \frac{c}{\lambda} = 2.1 * 10^ -15 [/tex]

(while you're at it tell me what's wrong with my code too, please)

f = c /lambda = 2.1x 10^-15 Hz

so then i know the frequency and the inverse of this is the period. The number of crests per second is the period (?) so the frequency gives the number of crests per second??

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# Homework Help: Simple Physics Question

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