 This one says the frequency of radiation used in microwave ovens sold in the U.S. is 2.45 gigahertz. What is the wavelength of this radiation in meters? Okay, so gigahertz. Wanting the wavelength. So in order to do this, we need to remember that equation, okay? So what was that equation? The speed of light equals the wavelength times the frequency. The speed of light always going to be given to you equals 2.99 per second or 3.00. Very similar. So in order to get the wavelength, we're going to have to rearrange this equation. C divided by V or nu. Remember this is in per second, right? Or seconds. Gigahertz is not per second. We need to get it to hertz, to get it to per second, right? So we need to come first. So if you guys remember, if you guys have this one, if you guys don't know, go back there anyway. Okay, so one gigahertz is one times ten to the time of two minutes. So let's rearrange this equation in such a way so it'll be easy for us to cancel out, or we'll say C times one over nu. So remember, hertz here, another way to write that is 2.45 times ten to the nine per one second. Right? Something like that. So we're going to write this out. 2.998 times ten to the eight meters per one second. And this is the inverse of that one second divided by 2.45 times ten to the ninth seconds canceled. And we're left with units of meters. Okay? So that not only is the units that they told us, but just thinking, right? That's a good unit for a length. Okay? So meters is a good unit for a length. So let's go ahead and figure out what the answer is. So I got 0.122. That's how long the wavelength was, a microwave oven. This wave is. Okay? Is there any questions on doing something like that? Again, you don't have to go so far as to break it all apart, but if it helps you to cancel out your units, go ahead and do so. Okay? Questions? Can I kill it?