Physics 105 Problems in Real Life

I spent many years helping physics 105 students work problems about someone throwing a ball off a hill with some sort of initial velocity where they have to figure out what the time of flight is, or the final distance or something like that.  A common comment is that no one does this in real life.  I've said it myself many times.

This week at work, we had something break.  It sits up fairly high off the floor, and threw some broken pieces across the room.  The details aren't important, but this was a bit of a safety hazard, as things aren't supposed to fly across the room.  As part of the report on what happened, they wanted to come up with an estimate of how fast the pieces were moving across the room, as a gauge of how dangerous the event really was.  So they came to me.  Finally, my skills are fully utilized!  With a few simple formulas I was able to calculate the initial velocity of the objects based on their final location, initial height and initial angle.  Sure, the calculation isn't perfect.  I can only guess a reasonable range of angles (though, because of other things in the room, and, you know, the ceiling, I can do pretty good on that) and we're neglecting friction (as always!), but the point is, I was finally able to use those very basic equations for motion in two dimensions to solve a real problem at work!

Soccer Improvements

So, the big soccer tournament in Europe has now gone 4 hours without a goal.  Two consecutive matches (England vs. Italy and Spain vs. Portugal) have now ended in 0-0 ties despite the 30 extra minutes of playing time.  Both games were decided with penalty kicks (with both Italy and Spain winning 4-2).  No one much likes this method for finishing soccer games.  Even the biggest soccer fans who ardently defend the game from the usual criticisms (too boring, not enough scoring, etc.) seem to agree (in my experience) that the current system isn't ideal.  (Another maddening aspect of the current system is when a team like England seems to spend the last half hour of a game playing for a tie so they can hope to win in the coin-flip that is PKs.  Apparently they didn't remember that England never wins in PKs.)  I was discussing with a co-worker what adjustments could be made:

1. Play until someone wins.  Continue with 15 minute overtime periods until someone is winning at the end of one of them.  Pro: Simple.  Doesn't "change the game".  It's like basketball (and many other sports) which has a potentially unlimited number of overtimes.  Cons: With the substitution rules in soccer, this becomes a crazy contest of conditioning very quickly.  Could devolve into a bunch of tired guys incapable of making good team plays, like in basketball when everyone is tired and the game turns into a series of plays where one guy tries to outrun everyone else.  He then either scores or doesn't, but now he's so tired he takes 3 plays off and someone else summons a burst of energy.  Maybe if they granted each team a new sub for each extra period, then this would test the talent of the reserve players.  (Similar to basketball OTs leading to players fouling out and bench players getting a greater roll, sometimes.)

2. Start taking players off the field.  At set intervals, change to 10-on-10, then 9-on-9, and so on until someone wins.  Pro: Opening up the field should stimulate scoring, right?  Cons: Too weird.  If it goes very far, 8-on-8 isn't real soccer anymore.  Plus, that much space will lead to even more running for the remaining players making this perhaps an even bigger contest of conditioning.  I don't like this one.

3. Make the goal bigger at periodic intervals.  In today's world, it's easy to make goals that could be adjusted quickly and accurately.  So every 15 minutes, crank the goal posts another foot apart, and another foot higher.  Pros: Increases scoring, particularly the likelihood of winning a game with an awesome shot from long distance.  Should keep teams playing aggressively, because they know their goal keeper is going to be increasingly less effective.  Cons: Could have equipment malfunction.

I like option #3 the best.  But, as always, I'd be curious to hear your ideas.

Do Not Eat List

My own personal Do Not Eat List has officially been incremented by one.  It now stands at:

• Fish
• Peas
• Kiwi
• Pinto Beans
• Chickpeas / Garbanzo Beans

Other than fish (nasty things, those) I generally like the things on the list.  They just don't like me.  The chickpea was the most recent, reluctant addition.  Not so much because they're a particular favorite of mine (I'm rather ambivalent), but because they're a favorite of Shannon's, and she does the cooking.  Unfortunately, repeated testing showed a strong correlation between eating chickpeas and feeling unwell.  That's really the best word I have for it: unwell.  I haven't had fish, peas or kiwi in years, but as for the chickpeas, they just make me feel very uncomfortable.  I wish I had better words for it, but I don't.  The feeling is centered in my chest/lung area, and it feels vaguely that if I could just get in a comfortable position things would feel better, but it turns out that there is no squirming in your seat that really makes a big effect on your chest.  The feeling goes away in an hour or so.  There's no breathing problems, or really any other symptoms.  But, who wants to eat something that is all but guaranteed to make you feel lousy afterward?  (Other than chocolate milk, of course.)

Getting Old

Evidently, Brett thinks I'm getting old.  That's undeniable, really.  We're all getting old.  But then I realized something that was simply too good to waste in a comment where many people might not see it:

Brett, I'm not getting old as fast as you are.

I live at a lower elevation than Brett, but even more importantly, at a higher latitude.  The latitude is important because the earth bulges at the equator to the tune of 26.54 miles.  So, I'm closer to the center of the earth than Brett.  That leaves Brett at a higher gravitational potential, and per the General Theory of Relativity, time moves faster for him.  It's called gravitational time dilation.  So if you want to stay young longer (compared to others), move toward the poles.  (Or dig a really deep hole.)  And in a few million (billion?) years, Brett will end up older than me*.

* Neglecting of course that Brett spent about 18 years living more polar than I, then we were about the same for the next 6 years, and I've only got about 6 years of living more polar of he does.  Though, the current margin is the largest to date.

Birds

One of the things I love most about Michigan is the birds.  Yeah, that sounds a bit silly, because I wouldn't ever have thought of myself as someone to get too worked up over birds, but there you have it: I like 'em.  (This is also a commentary about my general feelings about living in Michigan: it's not that different!  There is no major adjustment; as such, minor things like birds can move their way high up the list of good things about Michigan.)  For my western dwelling friends, I'd like to introduce you to my favorite two birds.

 

Cardinal

Like 14 states have the cardinal as their state bird, which is totally unoriginal, but I can see why.  (For the record, Michigan's state bird is the robin.)  Cardinals are strikingly red.  I love seeing such a bright color in nature.  There is one cardinal which I hate though: the one who sits in the tree outside my bedroom window and whistles his little heart out every stinking morning starting at 5 O'CLOCK IN THE FREAKING MORNING!!!  Other that him, I think cardinals are great. 

 

 

Red-winged Blackbird

I'd never heard of a red-winged blackbird prior to moving out here, but they're my favorite of them all.  Their name describes them pretty well; they're black with a patch of red (and a little bit of yellow) at the base of their wing.  As with most birds, we're primarily talking about the males here, because the females look pretty blah.  Sucks to be a girl bird, I guess.  The red-winged blackbirds live in the more wetland-type areas, which out here means in the ditches on the sides of the road (in the rural places).  This makes driving to and from work (I work next to a corn field) like a little adventure every day looking for these birds in the tall grass.  (I also get to look for deer on one of my two routes.)

photo borrowed from wikipedia

May Self Locomotion Update

Another record month!  Life is good when the weather is continually improving making it easier to get out and rack up miles.  My running picked up in May in preparation for a 10k.  Skipping basketball to run really helped, as basketball only counts for 1 mile per hour, and I replaced it with running 4 to 7 miles (in less time, too).  Shannon has also been racking up miles walking with the girls.  All of our effort has made major strides for the month; we've gone from being about 70 miles behind pace to only 14 at the end of the month.  In June we'll be spending a decent part of the month in Utah, so we'll have to make sure we keep it up and start building up miles before the weather turns in the fall.  We're kinda like bears preparing for winter.  Only we run walk and hike.

The numbers:
May total: 139.3 mi
Total through 5/31/12: 401.23 mi
March pace: 1645 mi/yr
Pace YTD: 688 mi/yr
Current Deficit: 14.07 mi


The Chart:

10k

Two weekends ago, I ran my very first 10k.  My results were widely reported and followed on facebook, so the world at large is already aware of the main points.  10 kilometers (6.2 miles).  44 minutes, 35 seconds.  4th in my age group (out of 20).  22nd over all (out of 251).  But you weren't satisfied with the facebook account.  How do I know?  Because you're here, which means you want every juicy little detail.

 

I finally got off my duff and registered for the race about a week in advance.  I'd been sitting on the fence for several weeks, and finally just did it.  Apparently that's the way I sign up for all my races now.  (And by all, I mean the 2 I've done in the last 3 years.)  There were both 5k and 10k races that morning, so when I got to the starting line there were many people there, including about half the ward.  For some odd reason, the 5k started first so as the crowd started condensing for that, I headed off to warm-up.  I'd read recently about the importance of warming up before a race, which, of course, makes sense.  The first mile always feels so awkward, until I get into a "groove" so to speak.  In a 10k, that means I'm spending about 15% of the race just getting comfortable.  So, the solution is to warm up for your race by running.  And that's where it gets tricky.  If you want to run 6.2 miles as fast a possible, how are you going to do that if you just went a mile or two to warm up, effectively turning your 10k into a 12 or 13k race?  But, undeterred (and trusting in the wisdom of the internet), I did about three quarters of a mile as slowly as possible.  This has been a big problem for me since switching to running in KSOs.  I have a hard time running slowly in them.  (I know, such a terrible problem to have.)  So, warmed up, I returned to the start line and found the 10k Mormons. 

 

Three of us started out together.  (I anticipated that they would be running the race, I don't think they expected to see me that morning.)  We stuck together for the first 1.5 to 2 miles (no, I was not taking notes while running) before we lost the first guy off the back.  I stayed with the other guy (who ended up finishing 9th overall, oh, and he's 15) until maybe the 2.5 mile mark.  I was trying to run a very even pace for the whole race, and generally did pretty good at that.  This was my first 10k race, but I'd done a few runs which were pretty close to 10k, so I went in feeling confident that I could do it under 47:00 with a stretch goal of beating 45:00.  They had people on the course shouting out times at each mile marker, so I could verify that I was able to stay on my 7:20/mi pace (45:30 10k).  (I don't have any fancy gps-enabled running watches (and I don't need them, thankyouverymuch) so I was wholly reliant on those updates each mile.  I do run with my stopwatch going, which I use to track all my runs, but also to check my cadence periodically.  I like to run at about 185 steps/minute.)  I don't remember all the mile times exactly, but I know I was pretty much on that 7:20 pace at the 5 mile mark (I think I was 10 or 20 seconds ahead total), at which point I cranked it up to as fast as I thought I could maintain for the 1.2 miles left, and hoped I didn't run out of gas.  I managed to pass several people in the last mile.  On the final stretch, with the finish line in sight, I could see 2 or 3 runners that were tantalizingly close, but I just couldn't make up any ground on them.  They were half a block or so in front of me, and I never really made any significant dent in the in the last quarter mile, so I finished without anyone real close to me.  Results show that I was 28 seconds ahead of the closest runner behind me (which was actually one of the largest gaps in the whole field, except for a couple doozies in the top 10.  2nd place was over 4 minutes behind the winner!) and I was 5 seconds behind the guy in front of me.  5 seconds sounds pretty close, and it is in many regards, but at the speeds we were running at it was probably about 70 feet.

 

So I finished.  I was very tired, but not fall-down-collapse-and-puke tired.  Once race results were posted, I was a bit disappointed to learn that the fellow 70 feet in front of me was 3rd in our age group.  So if I'd managed cut 6 seconds out of the previous 44 plus minutes of running, I would have had a top 3 finish (and a medal).  But, I remind myself that it's pretty rediculous to be upset when I'd managed to beat my stretch goal by 25 seconds and that it was the first 10k I've ever raced in my life.  I guess we'll have to leave championship trophies and medals until at least my second race.

 

As I mentioned, I did the race in my KSOs.  I saw only 2 or 3 other people wearing similar shoes.  I had 3 or 4 strangers stop me and ask what I thought of them.  I have no idea how to respond to a stranger in one sentence what they're like, other than to simply say "I like them.  They're a big adjustment though." (I know, 2 sentences.)  Shannon and the girls came and watched me finish, which was nice.  Probably pretty boring for them to go out there just to watch me run for about 10 seconds, but they claim to have liked it.