A laser pointer used in a lecture hall emits light at 650 nm. What is the frequency of this radiation?

Video transcript

Hi everyone today. We have a question asking us if the wavelength of visible light was nm, what is its frequency? So this one is pretty straightforward. We can use the formula speed of light equals wavelength times frequency and we want frequency to be isolated. So we divide both sides by wavelength. So frequency is going to equal the speed of light divided by the wavelength. So now we need to change our 869 million nanometers into meters. So we're going to have 869 nanometers and we'll have one nanometer on the bottom Times 10 to the - m and that equals 8. times 10 to the negative seven. And now we just gotta plug in our numbers. So our frequency is going to equal the speed of light, which is three Times 10 to the eight meters per second over 8.6, 9 times 10 to the -7 m. So our meters are going to cancel out And that equals 3.4, 5 times 10 to the 14th inverse seconds. So our answer here is C thank you for watching. Bye