[ATTACH=CONFIG]205[/ATTACH]Well I hope y'all have had a delightful week, I soitenly have, and I'm back with another discussion of (simplified) running based physics. The idea comes from the difficulty of running through mud while in a race, which I and several thousand other high-schoolers got to partake in at Genesee Valley Park. A quick background: yes it was a xc race, and due to the number of runners and weather conditions, the course was, to put it nicely, a mud pit. Down by the river, there is probably a 600m long section that was basically pure mud. Now for the physics. As many of you s-m-r-t smart people out there guessed, mud slows you down... Amazing! But why, and how much? In simple, probably incorrect terms, mud has a lower coefficient of friction than the usual grass (the actual numbers I don't know, computers don't like me very much...), and thus there is a lower force of friction. Now we all know that we need friction to move, but why is less friction so detrimental? Because (due to Newton's 3rd Law) every action has an equal and opposite reaction, so when you push against the ground, the ground will actually push back on you, propelling you forward. The lack of friction in mud causes you to slip and slide, lessening the force with which you push against the ground and therefore decreasing the force with which you move forward... So making you slower. As for how much, it is difficult to say, but on the 3-mile race course, times were slowed by approximately twenty seconds, which is quite a chunk of time! Hope you enjoyed learning more about running and its perils, my phellow phyziscistz