Answer
- The frequency of the radiation is:
$\nu \approx4.612\times10^{14}s^{-1}$
- The color red is associated with a wavelength of $650nm$.
Work Step by Step
*Strategy: We would use the formula $$\lambda\times\nu=c$$
in which
$\lambda$ : wavelength of radiation
$\nu$ : frequency of radiation
$c$ : speed of light (we would take the speed of light in a vacuum, meaning $c \approx2.998\times10^8m/s$)
- Step 1: Find the known variables
The laser pointer emits light at 650nm, so the wavelength of this radiation is: $\lambda = 650nm = 6.5\times10^{-7}m$.
- Step 2: Do the calculation according to the formula
The frequency of this radiation would be:
$\nu=\frac{c}{\lambda}=\frac{2.998\times10^{8}}{6.5\times10^{-7}}\approx4.612\times10^{14}s^{-1}$
- Step 3: Predict the color of this radiation
Looking up the electromagnetic spectrum, we see that a wavelength of $650nm$ would very likely lie in the red zone of the visible light. Therefore, red is associated with this wavelength
