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kateh516

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Everything posted by kateh516

  1. I believe most living things are born with some a basic understanding of physics. If I jump up, I'll come back down. We certainly know gravity, as it effects us every moment we are on Earth. I'd like to share an example of this. Recently, as I worked on some homework I had, my cat jumped up on the table. She walked around on it, exploring, for a few minutes then went to jump down. I noticed she did not do anything other than simply sliding her front paws off, the rest of her following after gravity took over. When her front paws left the table there was no longer the force of the table acting upon her. The force the table exerted up on her four paws was greater than the force of gravity acting on her in the downward direction. Once that barrier was gone, the only force left acting upon her was gravity. She landed, then trotted off, on some unknown mission that cats often have. To conclude this blog post, I would like to share a physics joke with you. It involves cats (which is how I'm tying it into this blog). Here goes: Two cats are sitting on a roof. Which one slides of first??? The one with the smallest mew!!!
  2. Okay, good point..... But I'm sure they would have said something
  3. The other day, after gym class, a few of my friends (you know who you are... I'm just protecting your privacy) stopped by the locker of one of said friends. His locker is known for the large amounts of food that is kept in there. After emptying out a Capri-Sun* box and a box of Little Bites Muffins* someone had the brilliant idea to put one of the boxes on their feet. He tried skating around on one foot without much success. After meandering along the halls, I thought someone should try wearing both. After a bit of experimentation with that we decided to start pulling each other around. The person wearing the boxes held onto another person who ran along, pulling them behind them. While nervously watching the security guard I was sure was going to approach us to tell us to stop I realized, "Hey! This would make a great physics blog post!" So, let us discuss the physics behind why this extremely fun activity (that, yes, I eventually did try) works!! If you tried to grab on to someone's back and have them pull you with your feet flat on the ground, you would most likely end up not getting very far. This is because the soles of your shoes are made to have a large amount of traction (a large coefficient of kinetic friction) so while you walk you don't slip all over the place. The boxes are the magic catalyst. When you put the boxes on your feet, the coefficient of kinetic friction greatly reduced, so while you are being pulled you can move across the top of the carpeted hallway without getting "stuck". It's also easier to start pulling someone because the coefficient of static friction is smaller that if you were wearing normal shoes. This means it is easier to get someone moving from rest. I highly suggest trying this with your friends sometime... but please be careful. Sometimes physics can get a little dangerous *DISCLAIMER: I was not sponsored by either of these companies, nor were any of my friends. I just thought it added to the blog
  4. Since we have moved out of the era of brick phones and indestructible Nokias, and have entered the world of fragile iPhones, the market for good phone cases has widened greatly. Cases used to be just stylistic choice. Now they are almost necessary since you are investing hundreds of dollars into an iPhone (they are totally worth it though). How does the case work to prevent damage to your phone though? When you drop your phone on a surface, the surface will act with an equal and opposite force on the iPhone. A large enough force is able to dent or shatter a phone, if dropped without any protection. Cases are built so that, on impact, the forces are distributed evenly across the phone. The materials used are also able to absorb some of the forces, again lessening the force that is exerted on the phone itself.
  5. Guitars, violins, violas, cellos... all examples of stringed instruments. There are many different ways to play them, but for the sake of this blog post I'm going to focus on plucking. Plucking is when whoever is playing the instrument uses their finger to pull up the string and let it go. I believe this is more commonly seen with guitars (I play violin and it doesn't happen to frequently in the pieces I play). All of these instruments have strings that are fixed on each end. When a string is plucked, the string vibrates at a given frequency. The vibration gives off a sound. As you place fingers down on the finger board, you change the length of the string. This will change the frequency (see the equation attached below). As the length changes (represented as lambda) the frequency will change producing different pitches.
  6. Nowadays, almost everyone has a camera right at their fingertips. With the invention of the smartphone, even the camera phone (remember when you were the coolest kid if you had a camera phone... or even just a cell phone?!!) pictures and picture taking has become an intricate part of everyday life. We've come a long way from the first ever camera phone to today's iPhone. The quality of the picture has improved greatly while remaining a lot smaller than a DSLR (digital single-lens reflex) camera. An iPhone will always be more convenient and more practical than carrying around a large camera, but the DSLR will take better pictures, hands down. This may seem obvious to most people. Yeah, a camera is going to take better pictures than the phone will. Let's discuss why this is true. In an iPhone, the lenses used are fixed. They do not have the capacity to zoom. The zooming you see on your screen is a digital zoom. The computer part of the camera takes the image and makes it larger. In a DSLR, the lenses rotate so that the focus is clear even after zooming a large distance. The DSLR lenses move individually so that the light being focused on the digital processor in the back of the camera is in it's best form. The mix of concave and convex lenses are what allows the camera to achieve the best possible zoom, and maintain the highest image quality. The iPhone is just to small to allow for space that would let the lenses move by themselves. They have to fit within a fixed amount of space. Yes, the iPhones have gotten larger in the past few releases (compare the iPhone 4 to the iPhone 6 plus- HUGE difference) but not enough to have a camera capable of what the DSLR is. So, DSLRs are a good investment for special occasions, but the iPhone will never be replaced by a DSLR simply because the iPhone is a more practical, everyday device.
  7. Today as I was rushing out of the house to my car, I dropped my water bottle on my driveway. As it hit the floor and bounced back up to me, I realized that it was an inelastic collision!! Actually my first thought was to get it from under the car so I could take it to school, but that's besides the point. Anyways, I knew it was an inelastic collision because some of the energy the water bottle started with, which was all potential energy because it was not in motion yet, was changed into sound energy as well as the energy used to create a dent in the bottle. So, the water bottle starts off with PE=mgh then is dropped and the energy changes into kinetic. When it hits the floor, the loss of energy is experienced as the bottle is deformed and the noise is heard. Due to conservation of energy, the bottle keeps some energy as not all of it is dissipated which is why it bounces back up off the ground.
  8. A book or watch the movie again with some of your favorite friends, because you can never get enough of that movie
  9. On Saturdays I usually have a riding lesson, which is always the highlight of my weekend. On my drive home from the barn, I was reflecting on the lesson and what I could improve on for next week. The goal of riding is to make all your cues to your horse invisible and move with the horse as much as possible. Sometimes, after asking for a faster speed from their horse, a rider gets "left behind"- as the horse gets faster the rider doesn't move with the horse and look like they aren't moving together. It can happen when the rider asks and is off balance or unprepared for the change or sometimes, as in today's case, you are riding a young (in the horse world it's called "green") horse. The horse I was riding today, Mystic, decided a few times to go a little bit faster than I had anticipated so I got left behind. After taking him over some ground poles at a trot, he started cantering (a faster speed than a trot). I could have helped him by making my clues more clear. In any case, on my drive home, my reflections turned to the physics of the matter. An object in motion wants to stay in motion, initially. When riding, two objects are trying to act as one, but when the horse changes speeds abruptly, the rider continues to move at the previous speed causing him or her to get "left behind". It's sort of like when you step on the brakes of the car and come to a stop really quickly, your body lurches forwards because it's trying to move at the same speed as it was before. The seat belt keeps you in place. With riding, it just works in the opposite direction with your body moving slower and the horse moving faster. And there is no seat belt keeping you on
  10. As mentioned in a few of my earlier blog posts, I am on my school's varsity volleyball team. Lots of the time, we have to do sprints across our thirty foot wide court as punishment for losing a drill or messing up too many times in row. I am always the last one to finish (it's absolutely terrible). Yes part of it is a lack of stamina, but the other day while running a very long set of sprints (we had to do 12 consecutive "down and backs" across our court), I was thinking about the physics and why I might be slower than the rest of the team. Then it hit me! As the tallest girl on the team (I'm 6'2") I have the largest mass of all the girls. Objects with larger masses have a harder time changing directions. It's momentum (p=mv)!! An object with a larger mass and some velocity will have greater momentum than an object with the same velocity but smaller mass. A larger momentum means a larger force is needed to stop the object. For a larger object to stop and change directions, it takes a longer amount of time to apply the force to stop it then start it again. So, although I am doing the same sprints as everyone else, it takes me a few seconds longer because of the extra time it takes to stop and then accelerate my larger mass (Or maybe I'm just terribly unathletic)
  11. Physics is everywhere. There has never been a more true statement. So let me take a minute to discuss the physics involved in a sport that I love and are blessed to participate in: horseback riding. There are many different disciplines in the Equestrian world, but for the case of this blog, I'm going to focus on the discipline I am most familiar with, jumping. The physics behind jumping is basic kinematics. To clear a fence, the horse and rider have to approach the jump with the right velocity. If the velocity is too small, the horse could refuse or knock a rail. In a competition, both of these would result in points deducted from your score. If the velocity is too large, you could over jump the fence, which, in the case of someone riding over multiple jumps, could mess up your approach to the next jump, not to mention use more energy than needed. When the horse and rider take off, there is a few seconds where the back hooves stay on the ground, creating an impulse force as they push away from the ground. While the horse leaves the ground to move over the jump, their kinetic energy changes to potential, reaching full potential energy over the maximum point over the jump. I've attached a few images of the movement of a horse and rider over a jump, to help see the actions I've described.
  12. kateh516

    Take a Hike.

    I like the picture
  13. A few days ago, my volleyball team traveled to another school for a match (which we won, even with the touch I called myself on that could have scored us the winning point if I hadn't) and for our trip home, the opposing team gave us a huge bag of apples. So as we rode the bus home we ate and then we had 15 apple cores and no idea what to do with them for the rest of our 45 minute bus ride home. An open window sparked an idea and with that I became the center for the discard of our apple cores. As I went to drop an apple core I worried about it hitting the car behind us. Luckily, my physics insight allowed me to realize I had no reason to fear. Although it looked like the apples were flying backwards, they weren't!!! Because I did not throw the apples, they moved in a straight (if we don't consider and updrafts, gusts of wind, etc.) path to the pavement below me. Due to our bus moving forwards and the apple moving down, the motion of the apple looked different than if we had watched it standing on the ground. So, due to the fact that apples are biodegradable and they won't hit another car if dropped out the window, you can also participate in an activity like this. Just please do not throw the apples at other cars or throw plastic out your window (the plastic is not biodegradable so it is littering).
  14. kateh516

    The Physics of Ballin'

    This is perfect!! Also, I think my "tackle" should have been mentioned in your incredible analysis of the physics of gym class ballin'
  15. In one of my late night musings, I asked myself, "Self, what would happen if gravity pulled us up towards the sky instead of down towards the ground?" and being a volleyball player, I wondered how that would affect the game. So let's create a situation to isolate some factors to get a better idea of what some possible outcomes would be. Let's say that, for this scenario, the court is the only area affected by the change in gravity. So the fans in the bleachers are seated and the coaches, players and refs on the sidelines are all able to stand like we do today. Pretty high tech court I'd say. So it would probably start off with a bunch of players on the ceiling. When the ball was served you would have a very hard time getting the ball to reach the other side because gravity would pull it up into the ceiling. Say someone did manage to get their serve over the net (which is still on the ground), once the ball gets to a hitter, they would have to hit with a much larger force to get a kill. Their arm swing would have to be greater than the force of gravity pulling on the ball. If the forces are unbalanced and the force from the hitter is larger that the force of gravity, the ball would be able to reach the floor of the court. The likelihood of anyone ever attempting to try this is probably very low due to the fact that it would make the game about 10000 times harder unless they changed some more variables of the scenario. It's an interesting idea to consider though, how a change in the direction of gravity would affect our daily lives. Especially when some variables of life are kept the same.
  16. kateh516

    First Post

    I agree with this statement
  17. kateh516

    First Blog Entry

    Hey same! I play violin too
  18. I don't think I know anyone who is NOT anxious for college applications... Why must they make it so complicated?!! Come June, I hope we look back and think that it wasn't as hard as we think it will be!
  19. Around school I'm probably known as "that really tall girl who rides horses" which is really a pretty accurate description of me. It does leave out some other things that are an essential part of who I am. I love the two classes I am the worst in: Physics and Math. I love history. AP European has been my favorite history class that I've taken so far, but I also enjoy learning about local history in my free time. I've been playing violin for almost 14 years now and play in my school's orchestra. As stated above, I ride horses which is my true passion in life and is something that will shape where I go in the future. I use my mentioned height to help my team out on the volleyball court. I decided to take AP Physics C for a few reasons. I took AP Physics 1 last year and loved it. I've always enjoyed science but Physics is by far my favorite. So why wouldn't I continue taking a class that I love? I also think that it is a class that will influence what kind of career and college major I decide to pursue. I hope this class will make me a better learner and a harder worker. I know that it will be a very challenging class, but along the way I hope the challenge will teach me the skills I need in college and life to successfully tackle challenging situations. I think I'm mostly excited for the extended learning that I will be getting. Hopefully, this class will expand upon the topics we learned last year to give me a better understanding of them. I think that the scariest part of this class will be the self-motivation I will need to accomplish my end goal: a 4 or higher on the AP exam. I will really need to motivate myself to do the learning required to be "good" at physics. I know that sometimes I get lazy with schoolwork, especially when the work gets more challenging, and I don't want that to happen to me this year. Along with this, of course I am worried about failing tests. It comes with the territory of the class, so I know that when I fail I should use it as a motivator to go back and learn the material more. Overall, I can't wait to see where this year takes me. I get the feeling that this is going to be a great year!
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