Friction, Forces, and Football

Let's see, Physics common in my life... You would not believe that I only just noticed a common example of friction as I was sitting at my computer, doing my Physics homework today. I was sitting in my rolling chair, and I realized "Hey! This chair has forces written all over it!" Not only does its weight, and therefore the normal force exerted by the floor, increase when I sit down on it, but the wheels have massive amounts of friction, and not just from the floor they roll on; the wheels have not exactly been lubricated anytime recently, so the wheel and axle create friction as well! I had never thought about it before. And, according to Newton's second law, the horizontal forces, mainly friction, are the reason that my horizontal push away from my desk does not make the chair travel very far! And then there are the forces that stop the chair quickly, such as the shoes and slippers that live about four feet behind my chair. :-) I feel sorry for them. Oh yeah, and in case you were wondering, that's my stuffed dog. His name is Taffy.
I really noticed a lot of physics this weekend. First on Friday night, I went to the football game at Aloha Stadium as part of the Marching Band, and I vividly noticed the travel pattern of the footbal on kickoffs (emphasized by the traditional trombone gliss following the ball), which was a parabola, as well as the velocity, both x and y. And then there was the Aloha Week Parade on Saturday morning, where I noticed that the normal force of the road on my body seems much increased when I'm marching on my toes, as they quickly started to hurt when I did, with the decreased surface area and all. As a result, my calf muscles are very stiff and sore right now. Oh, well, I'm used to it.