Paintballs & Diffusion

You can see the flaps on where you remove a plug to allow the 

bunkers to deflate 

Last Wednesday the Class Leadership Council of Colgate hosted LaserTag as a school event. I was one of the students who happened to be responsible for helping clean up the laser tag setup in Huntington on Wednesday night. The lights in the entire gymnasium had been shut off and portable black lights had been placed around the borders of the basketball courts. The company hired to host the event was named MightyPaintball. Two men in a Uhaul filled with equipment had placed around 20 inflatable 'bunkers' to be used as places of cover for the laser tag game. When it was time for clean up the other students and I were instructed to tip all the bunkers on there side, search for plastic flap, and unscrew the green colored plugs keeping the air trapped. Once the hole was open, we dragged the bunkers and arranged them along the gym wall in descending size order. One of the MightyPaintball workers walked down the line with some fan power tool that helped remove the air from the inflatables quicker.

As I was working I had a good deal of fun pressing on the sides of the bunkers and hearing the whoosh that was created as I forced air to be expelled from the inflatables at a faster rate. I began to get curious however of what the normal rate of diffusion was for the air as it escaped these assorted inflatables. How far a distance would it be for a molecule from one side of the bunker to diffuse out of the hole. iI decided to measure one of the smallest inflatables, a red cube, and found that it was about 3 meters high. Assuming two dimensional motion where a single air molecule must diagonally from the upper left corner of the cube to hole in the bottom right it must travel a distance f 420 cm. With the diffusion rate of air googled to be 0.176 cm^2/s it would take approximately 596.6 s or about 10 minutes. So I guess it was good we had a power tool to help deflate all the bunkers or else clean up would of taken a lot longer.