Using a mixture of CO2, N2, and sometimes He, CO2 lasers emit a wavelength of 10.6 um. At power of 0.100 kW, such lasers are used for surgery. How many photons per second does a CO2 laser deliver to the tissue during its use in an operation?

Video transcript

Welcome back, everyone. We are making observations about a nitrogen laser beam. We are told that it operates at a wavelength of 337 nanometers or 337 times 10 to the negative ninth meters. We are also told that it has an output power of 0. watts. And we are tasked with finding the number of photons per second produced by our nitrogen laser. Well, here is how we are going to do this. Let me go ahead and change colors here real quick. We know that power is equal to our total energy divided by our time. But we know that our total energy is calculated by the number of photons times our energy divided by time. Solving for our rate of photons per second. What we get is that our rate is equal to our power divided by our energy. We have our power already. But what is going to be our energy? Our energy is calculated by planks constant times the speed of light divided by our wavelength. We have all of those numbers. So let me go ahead and calculate that value we have the our energy is equal to 6.63 times 10 to the negative 34th times three times 10 to the eighth, all divided by 3, 37 times 10 to the negative ninth. What we get when we plug this into our calculator is 5.9 times 10 to the negative 19th Jews. So let me change colors one more time. Here we are now finally ready to calculate our rate of photons emitted per second here. What this is equal to is our power of 0.3 divided by our energy of 5.9 times 10 to the negative 19th. What this gives us when we plug it into our calculator is a final answer of five point oh eight times 10 to the 17th, which corresponds to our final answer. Choice of D. Thank you all so much for watching. I hope this video helped. We will see you all in the next one.