Greg Rundlett: > I just offer an interesting example of how math ain't that hard, and > can be used to solve "fun" problems. The basic question at hand was > "How fast does the machine pitch? (compared to a major-league > pitcher)". The basic answer could be found through some unit > conversion and cross multiplication.
I'd argue that almost anything that has units is physics. Solving for time given speed and distance is that. A lot of math involves dimensionless quanties. Not all - radians vs. degrees comes to mind immediately. Solving x^2 + 2*x + 6 = 0 involves imaginary numbers, but those aren't units. > Greg Rundlett wrote: > > > Philosophically and sociologically, I'm asking why somebody who worked > > there wouldn't solve these problems out of curiosity. Because they > > don't know how? Because they don't care? Because they were > > conditioned by social norms to believe the subject is too difficult or > > uncool? I was surprised when I took Biology in high school that nearly all the other students knew nothing about the subject matter. Apparently I scored some good brownie points with the teacher by pointing out a typo in the chemical formula for sucrose. I don't know what causes kids to be interested in a subject - my sister and her husband are marine biologists, their daughter isn't very interested in science. Nor is my daughter. > > I'd wonder if > > air-resistance and distance factored into the two scenarios to create > > any difference. Is there a (marked) difference in deccelleration > > (initial velocity - final velocity) between the two environments due > > to the almost double distance traveled by a major-league fast ball? Most high school physics ignores such second level effects. There is a book titled "The Physics of Baseball," I believe, I don't own it though. > Also, to bring this more on topic, as a push for FOSS, with open source > software you could use available source code for ballistics and > aerodynamic modeling in order to find the exact answer here. In a > closed source world, you'd have to start from scratch... I'm not terribly interested in baseball physics, though I didn't spend some time last summer reading a few web pages about curve balls (they curve down, not sideways!) fastballs (they aren't just fast, they have a lift component) and some of the others. At least it explains why curve balls often result in ground balls and why high fastballs are hard to hit. My guess is that the surface roughness and lacing greatly affect the second order effects and you my have trouble finding code anywhere that models them well. And anything you find will cry out for extension. > From: "mike miller" <[EMAIL PROTECTED]> > ... I doubt most batters could tell the difference > between a 90mph and a 91.66mph pitch. Well, that's about 2%, over 60' that's 1.2' and several degrees difference in the direction the ball goes. > From: Jim Kuzdrall <[EMAIL PROTECTED]> > I did figure it out - approximately. The Reynold's number is > 180000, assuming the ball is a smooth sphere of 70mm diameter (I didn't > look up the actual size). The drag coefficient is .5, which results in > a retarding force of 1.8 Newtons. Sigh, one course I didn't take in college and kinda wish I had was Fluid Dynamics. I really should read up on that. I did show some movies in a FD class showing turbulent & laminar drag. > That means the initial velocity must be 44m/s to arrive at the plate > at 40m/s (90mph). mlb.com has a "gameday" display that shows data about each pitch, I think that's about the right amount of drag. It also shows data about the arc of the ball and whatnot. _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
