Question

The laser in an audio compact disc player uses light with a wavelength of `7.8 * 10^2` `nm`. What is the frequency of this light?

Answer 1

`nu=3.8xx10^(14)s^(-1)`

Explanation:

The relationship between wavelength `lambda` and frequency `nu` is:

`nu=c/(lambda)`

where, `c=3.0xx10^8m/s` is the speed of light

therefore, `nu=(3.0xx10^8cancel(m)/s)/(7.8xx10^(-7)cancel(m))=3.8xx10^(14)s^(-1)`