 Okay, so since we just did that lecture on this equation, c equals nu times lambda, let's do a problem on it. So what's the frequency in hertz of a gamma ray with a wavelength of 3.56 times 10 to the negative 11 fields? Let's write it down that way. So this is something you're going to have to remember this equation in this constant. So what are we looking for? It's a frequency, right? So we're going to have to rearrange this equation to isolate the variable frequency in order to do that. We get nu equals the speed of light over lambda. So we have the speed of light here, 3.0 times 10 to the negative 8 meters per one second. And we know the wavelength. So this one's pretty easy. Again, like you said, we didn't have to invert anything. So notice this is the same thing as saying cancel out your units like I do in this problem, this one. So of course this is going to go to 3.56. So I got, hopefully you got, 3.43 times 10 to the 18 per second, remember? And remember what we said about these per seconds? It means hertz. So the answer is going to be 8.43 times 10 to the, it's the frequency of this gamma over ray with this wavelength of 3.56 times 10 to the negative 11 meters is 8.43 times 10 to the 18 per second. Okay, is everybody okay with that? So notice here, one other thing I guess we should notice, real small wavelengths, right? Very, very tiny. So the frequency should be very big. Everybody okay with that? Any questions on this one?