welcome to our first example video, looking at the microscopic and macroscopic picture in the kinetic theory of of an air molecule traveling through, traveling around inside a one liter box at 25 degrees Celsius. So for this, in order to find the mean free path, we write down our equation which again, a bunch of constance multiplied by the number density multiplied by the radius squared because most air is mostly nitrogen and oxygen, that is. And to an 02 this is gonna be approximated is a dye atomic gas, which means we have r equals one times 10 to the negative 10 m. And then we can use the ideal gas law in order to calculate what the number density and over V is going to be, we find is going to be p over K b times t plugging in our numbers here, where we're at one atmosphere and 298 Kelvin, we come up with a mean free path of 0.23 microns. Give you some idea. The width of a human hair is approximately tend to 100. My Cron's okay, and this is moving approximately 0.23 Mike Rounds before it has a collision. So all the air around you right now moves about this far before it runs into another air molecule and gets deflected.