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Ben Shelton

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Ben Shelton last won the day on November 20 2013

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  1. when you put a shovel on an old picnic table in your backyard and a leg of the table snaps, it's time for a new table. Problem is, the table can't be thrown away or used for firewood (some parts are just too rotted for anything put the garbage) as it is. It had to be taken apart. The first thing I did was pry off the crossbeams on the table's underside. The crowbar had to be placed at a 90 degree angle and then hammered underneath the crossbeam and pulled. The trick was to make sure the sideways pressure on the crowbar was transferred into the right place. Without something holding the main beams in place, the crossbeams would just pull up the main beams, because energy is always transferred and an object in motion (the main beams nailed to the cross beams) will remain in motion unless acted on by an outside force (my foot). With nowhere else to go, the nails where forced to separate from the board. Next I had to brake up all the beams with an ax. the acceleration of my ax would transfer onto the board, driving the head into the board. The motion I made with each swing was a half circle. sometimes the force would be so great and the wood so rotten, the energy would be transferred too fast for the board and it would break on the first try! These demonstrate two basic laws of physics: an object in motion will stay in motion unless acted on by an outside force; and energy will never be destroyed or created, only transferred. That table sure was destroyed though!
  2. In one of my previous posts I examined the physics of The James Bond movie Skyfall. I concluded that Bond's survival was pyisickly impossible due to a fall from a bridge. In this post I will analyze another spy- Jason Bourne- and a certain (spoiler alert) plunge he takes at the end of his third movie. Bourne jumps off a skyscraper and goes into a perfect pencil dive to escape his pursuers. To discover his velocity when he hit the water, I will apply the basic equation v=d/t. The time he fell is approximately 4 seconds, and the distance he fell was approximately 100 meters (The building height is not on the internet). Therefore he hit the water at 25 meters per second, give or take. This is a perfectly survivable fall velocity, given that he went into the water with the least possible velocity.
  3. I am studying forms of alternative energy for Participation in government class. Since we are studying waves in physics right now, I figured that I would focus on wave energy and how exactly it works. The generators and power cables are placed in the water, usually close to shore. The magnets are placed in a mechanical harmony with the electric wires, like we learned in the last unit with generators. The wave generator works the same way, except instead of fossil fuels the generator uses the mechanical energy generated by the wave. In addition to the up and down motion of a wave, there is circular motion generated to anything floating on top. A floating object is actually moved in a circle, which generates the mechanical power needed to generate electricity. I will post a video of this shortly, when I can figure out how to get the file onto my computer. It's actually pretty interesting!
  4. So my snow day was going perfect untill after lunch. I was doing my dishes and then I heard this metalic clang and the dishwasher door became twice as heavy. I investigated and I saw that the Door is (was) attatched to two springs that slow it down as it nears the floor. One of those had snapped. I should add that I am always extremely carefull with that device and it is 14 years old, so it's not my fault (but I still had to fix it). The phyisics behind the contraption are interesting. Before we did the spring unit I thoght that a springs only purpose was to launch things, as illistrated in various sicentificly accurate educational cartoons. But clearly this spring's purpose was to absorb force and slow the heavy door down. To figure out why it broke, and how to fix it, I used the equation Fs ( force on the spring) equals k(spring constant) times X (change in spring leght from the equilibrium position.) Unfortanately, I was not able to find the constant of the spring, so I could not find the force acting on it. However, I noticed that the spring that broke was set up so that there was always at least a small ammount of tension on it. It went from 12 inches from equilibrium when the door was open to one inch when it was closed. It had not been in an equilibrium position for 14 years! It's a wonder it did not break sooner. Fixing the spring was a simple (well, I say that..) matter of getting the spring to an equilibrium position by attatching it closer to the door without getting it so close that the spring would be comppresed and push back on the conecter peice holding it in place and fly off into the dark underbelly of pipes and hoses and dust and spiderwebs that lies underneath the dish washer. It was a trial and error process (with some cursing). The moral of the story? A. Never keep a spring tense longer than it needs to be; and B; anything will always take you twice as long as think it will if you are inexperienced (and dumb enough to tell your parents about the funny noise you heard your dishwasher make)
  5. So I watched the latest James Bond movie, Skyfall, for the third time yesterday (thank you netflix) and noticed some irregularites. If you don't want to have the first fifteen muinites of the movie spoiled read no further. So Bond gets shot off the top of a moveing train, falls from an insane hight into a moveing river, and then falls off an equally high water fall. Here's the thing: he survives! I did some phyisics to find out if this was phyisicly possible. The bridge Bond fell off was three hundred and twenty two feet high. From that hight water is like concrete because it's tension will not break at the speed Bond was going when he hit it. to find out that speed I have to add his initial velocity (zero) to his acceleration (9.81 meters per second squared) times the time of his fall ( six seconds). Bond's velocity when he hits the water is 58.86 meters per second. To double check my work, I will also use the other formula, because the movie showed the fall in a couple shots and I don't know if the time is accurate. initial velocity squared( 0) plus two times Acceleration (9.81 meters per second squared) times distiance (322 feet = 98 meters). This time I got 31.1 meters per second squared. I'm more inclined to trust the second awnser because I know the hight for sure. This converts to about 129 miles per hour for the first velocity, and 80 for the second. Any human body hitting the water at those speeds would encounter massive ammounts of surface tension, like hitting a brick wall, and just shatter on impact. The verdict: James Bond is now immune to the laws of phyisics as well as enemy spies and hitmen(and thier tanks and submarines and assult planes and helicopters and everything else). Apperently he only lives twice, but never needs to use that second life because he has a licence to never be killed by anything.
  6. the war of american independence was a revolution in more ways than one. In addition to all the wonderfull things like Individual rights, self reliance, independce, democracy, and freedom, the war for independence broght about an incredible change in the nature of war. The patriots where up against the most heavially armed machine of brute force in the worold, the brittish empire. thier navy and army so far surpassed the rest of the worold, they could hold thier own against an alliance of three european countries. To defeat this mass of oppressive force, the patriots would need corage, tenacity, and an entirely new way of wageing war. There was one peice of brilliantly engineered technology that changed the course of the war: the rifle. Up untill then guns had had a smoth inside barrel, causeing the bullet to fly somewhat innaccurately. This changed with the invention of the rifle. This allowed for putting groves on the inside of the barrell, giveing a fired projectile a spin. This is where the phyiscs comes in. Because the bullet is spining, the force is going in a circuliar direction towards a central axis, makeing it highly unlikely to veer off corase. the same pricipal applies for speed. because bullets spin, they cut throgh air resistance and fight gravity better than a musket ball would, enableing them to travell farther as well as striaghter. When the colinists got thier hands on these, the battles started fareing better. At the battle of Saratoga, which many consider America's greatest victory and the turning point of the war, an Irish American named Timothy Murphy shot brittish general Simon Fraser with one of the new rifles at an incredible distance (for the time) of 300 yards, iciteing the brittish to retreat. This new technology, along with the American tactic of acctually takeing cover behind trees instead of standing in an open feild, enabled a small and heroic group of patriots to hold thier own against the worold's mightiest empire. Everytime an American practices his rights, he or she can thank phyisics.
  7. When a dart is thrown into a dartboard, there are a lot of phyisics involved. For one thing, there is the pricipal that an object at rest will continue in it's speed and direction unless acted on by an outside force. If there where no outside forces acting on the dart, everyone would hit the bullsye every time. But, there is gravity acting on the dart, pushing it to the ground, as well as air resistance slowing it down. Consequently, you have to factor these in when you throw the dart, otherwise you end up hitting the wall. I've found that by aiming a little bit above where I want to hit, depending on the range, I can be fairly accurate. In "sniper talk" this is called figuring out the "drop" of the projectile for cirtian distances. Some can get to the point where they know off the top of their heads how much a projectile will drop in 10 yard increments. Every time a projectile, like a dart, is put in to motion with the intention of hitting something, a miniature phyisics problem must be done mentally. (If only for an aproxiamate estimate within a person's head. Apperently even when I upload the vedios to youtube, the website won't let me put them on, claiming I don't select a file even thogh I just did. So no vedios with this post, unfortunately, but they are on youtube under my name if you want to check them out.
  8. An indoor track has a few advantages over an outdoor one. For one thing, a person dosen't have to worry about rain and wind that typicly slow a runner down when you run outside. Another advantage is that the air conditions are always the same: 79 deggrees and dry. But the greatest advantage of all is that you have to turn twice as much, because the track is only half as big around. Just kidding, only the first one was an advantage. The fact truth is that RIT could give death valley a run for it's money. The "cottonmouth" ( dry throat) weighs especially heavy on a sick person like me who trys to run. But the real killer is the turns. Those are the reason you add 10 to twenty seconds to your outdoor best time to get your indoor best. Its because acceleration involves not only increaseing the speed of an object, but also changeing it's direction, because acceleration is a vector. When an athelete changes directions, the energy required to lean for the turn is energy that could be used to speed up and start passing pepole twards the end of the race. The turns are long and the straightaways are short, so there is twice the acceleration, twice the energy spent on turning, as in an outdoor track race. and that is why runners almost always seem to get slower in indoor track. Personally, I long for the long straightaways, cool brezzes, cool, moist air, and sweet 60 deggree weather of outdoor track. Indoor's the best way to stay in shape thoght!
  9. Juggleing is a great deal harder than it looks. This is because a great deal of phyisics goes into each throw. Each time you throw, you have to calculate in your head the speed of the ball, the force you applied to it and how long it will take gravity to overcome it, and where your hand needs to be at what time. This all needs to be done within fractions of a second. attatched is a vedio of me explaining in greater detail this pricipal as well as trying it out. Will I succued like a profesional clown? or will I fail miserably like a... clown? find out! When I figure out how to publish the vedio
  10. So It gets dark before 5 O'Clock nowadays. I state this not becuase I think you, the reader, are incable of interpreting a clock ( I assume you are because you are literate enogh to read ) but because this fact has some bearing on the phyisics of running. When I foolishly decided put off starting my training run untill four fifteen, I found myself in the middle of the woods forty minuites later with the sun sinking below the horizon and three miles of trails left to navigate. Phyisicly speaking, A couple things happened to me at that point. First, the subconience fear kicks in, the effect of too many horror movies, that I will be eaten by cyotes or kiddnaped or murdered by some deranged phycopath. This produces the aldrenaline rush, which sends me flying throgh the woods at an abnormal speed. Because every shadow is a potential lurking threat to my scared brain, I fail to look at the ground, and I forget newton's third law. Applied here, that means that when sneaker toe applies force to an unseen root, this root will push back and cause a runner to accelrate downward in a parabolic arc toward the ground, because his momentum will be stopped suddenly and unexpectedly. Thankfully, I cauhgt myself and managed to keep my fear under controll for the rest of the trip back. But a runner will stay in motion at a constant speed unless acted upon by the completion of his goal, and I ran, abiet carefully, all the way home. Moral of the story: always bring a flashlight. P.S. don't judge me on the spelling my laptop does not have a right click and I have no way to spell check that I know of. You know you all rely on it as much as I do:)
  11. Catapults are a subject that we are all framiliar with here. But these devices have had a profound affect on the history of the worold, as well as human understanding of phyisics. They where developed in ancient times, first used on the battlefield by Alexander the great. The mass of the object being thrown had to be aproximated, as well as the size of the launcher, how gravity would affect the missile, and the distance to the target. This acctually led to the development of some of the first math based phyisics, so that Alexander and his commanders could better hit their targets. These devices enabled Alexander to conquer much of the known world, truimphing over his enemies' superior numbers, city walls, and even elephants. This resulted in a spread of Greek civilization and golden age, as well as spreading learning (includeing phyisics) and one important Greek invention we enjoy very much today: democracy.
  12. Phyisics has had a tremendous influence on history, in all times and and places. The first instance of goes all the way back to cavemen times. The cavemen origionaly hunted with clubs. There wasen't much phyisics to this, just jump out at an animal and swing. However, as anyone who has ever seen a deer knows, animals tend to bolt at the slightest noise and it is impossible to out sprint four legs. So some anoynomuos Albert Einstien of an 10,000 B.C. created a spear. This way, if he failed at sneaking, he could throw his spear. When throwing, Albert the caveman would have to figure out the trajectory of his spear relative to the speed and angle of his quary( as well as his own velocity if applicable ) as well as the downward acceleration due to gravity. Given that this is melenium before any kind of writen carachters, let alone math, it is safe to assume Albert did this by trial and error. Becuse albert was more well fed, he could afford to do things like develop fire, the wheel, and all those other things we take for granted. Thank you, albert the caveman!
  13. The catapult project obviously has a lot of phyisics attatched to it. When we tested our catapult, we had some trouble getting it to go forward instead of backward. We where able to fix it by modifying our throwing mechanism to accomodate a ball. What we did not account for, however, was that the baseball we where useing in place of a softball was not the same size or weight as an acctuall softball. Because of this, we could only get the softball to acctually go forward once on test day. what we should have done was make a better throwing mechanism and acctually bought a softball to do a test with.
  14. Cross country and track running are like any other sport, in that they both involve a lot of phyisics. When a runner goes out for a training run at 8 miles per hour, they will try to hold that speed for the whole run ( one to two hours.) This means no acceleration after the inital speed is reached. In a race, however, it is different. In, say, a three mile race, if a runner starts with a 5:25 mile, the goal is to accelerate every mile, and get faster as the end of the race gets closer. This seems counterintuitive, because the farther you run, the more tired you get, but that's how you get good times and beat other runners. When a runner gets home after a race or a hard workout, a different set of laws applies: a tired runner tends to remain at rest unless acted on by an unbalanced force ( the smell of food).
  15. I am exited for the catapults and bottle rockets too.
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