Physics C and How it Relates to Me

One of my favorite things to do during the summer is water skiing. I don't go very often, but when I do, I love the satisfaction of getting up out of the water. In order to get up, you have to point your skis upward out of the water. By doing so, the skis are able to apply a force perpendicular to the direction of the velocity of the boat as the boat accelerates in the forward direction. This perpendicular force prevents the skier from face planting in the water. Then, you must tilt your skis to a lesser degree (as measured from the horizontal) in order to be pulled out of the water. By tilting your skis, the water applies a force, which has a component in the upward direction. This upward force pushes your skis upward until they are above the water level. The skis will remain afloat as long as the normal force to the skier, which is applied by the water, is equal to the downward force of gravity on the skier. Additionally, in order to avoid faceplanting in the water, the skier must recognize that as the boat accelerates in the forward direction, it will pull him/her forward. The skier then must apply an equal and opposite force to counter the force of the boat.

One of my favorite sports to play is ping pong. I've always had a ping pong table in my basement and play with my brothers and with friends pretty frequently. I've always been amazed at the skill of Olympic table tennis players. If you've never seen Olympic table tennis, It's amazing how fast the little ball is hit back and forth between the two players. Sometimes it goes so fast that you can barely see it. The physics behind the game can explain why these Olympic athletes are so skilled at the game. In serving the ball, a player must throw the ball out of his hand at least 6 inches in the air and then hit the ball so that it bounces once on his/her side and once on his opponent's side. According to Newton's second law of motion, the greater the force that is applied to an object, the greater the object will accelerate. Olympic table tennis players hit the ball with great force, causing it to accelerate so rapidly that the ball can hardly be seen. Although they can serve the ball with such great force, their opponent is still able to return the ball without moving his paddle very much at all. The opponent does not need to worry very much about applying a great force to the ball as it comes towards him/her because of Newton's third law. An action force always has an equal and opposite reaction force. As the ball's inertia causes it to travel towards the opponent, it applies a force to the paddle, and the paddle applies an equal and opposite reaction force, causing the ball to accelerate in the opposite direction. Therefore, the force causing the ball to accelerate back towards the player who served it is caused mostly by the inertia of the ball. Watch this video below showing the best 10 table tennis rallies of all time. 

I'm gonna be honest, I hate running. I love athletic games that require running, but I hate running just to exercise outside of the context of a sport. One of the most dreaded days of the IHS soccer season is the first day of double sessions. We have to run a mile and a half around the track in under 9 minutes and 20 seconds. It's a pretty difficult time to get, especially for those that don't do very much training beforehand. It requires a lot of mental toughness and determination. I can't begin to imagine the training that is required to break Olympic records in long distance running. High level athletes understand the difficulty in running long distance, and in order to better their performance, they consider the physics of running. The basic physics of running are pretty simple. A runner applies a force to the ground that is directed opposite the direction they are running. Then Newton's third law kicks in, and the ground applies and equal and opposite reaction force on the running, causing their body to be propelled upward and forward. In order to break records, runners must consider more than just the basic physics associate with their sport. According to Real World Physics Problems, in a 400m race  "the runner should accelerate as fast as possible for 1.78 seconds. This will enable him to reach a speed near his maximum. He should then maintain this speed for as long as he can. This speed will be such that 0.86 seconds before the end of the race his energy is entirely used up, and after this point is reached his running speed will begin to drop." Pretty crazy to think that runners consider how long to accelerate down to the millisecond. Watch this video to see the world record for the 400m, set by Wayde van Niekerk in Rio in 2016.

One of the only games that I think I'll never get sick of playing is Spikeball. Spikeball is a new sport similar to both volleyball and foursquare. Two two person teams gather around a circular net. A point begins when a player serves a Spikeball by hitting the ball on the net so that it ricochets to the other team. The opposing team has three hits between them to hit the ball back on the net. If they do hit the ball back on the net, then the other team gains possession of the ball, meaning that they then have three hits between them to hit the ball back on the net. When a team does not hit the ball back on the net, the other team scores. Pretty cool, right? The game also involves physics, specifically Newton's laws of motion. In serving a ball, a player applies a force on the ball that causes the ball to accelerate and hit the net. The greater the applied force, the greater the ball will accelerate. Newton's third law of motion is demonstrated when the ball hits the net and ricochets off. Every action force has an equal and opposite reaction force - when the ball hits the net, the ball applies a force to the net, causing the net to react by applying an equal and opposite force on the ball. To get a better idea of how the game works, watch the tutorial video below.

This past Friday, our class attempted the "Shoot Your Grade" lab, in which we had to place a book on the floor where we expected a projected ball would hit. As a class, we all failed the lab because the book was not placed where the ball hit. The main reason for our failure was lack of communication between our class mates. Doing a lab with 25 people and having all those people working to solve the same problem can easily be chaotic and confusing, and it definitely was. If we had established agreed upon measurements, our final answers for where to place the book would have ideally agreed with each other (as long as people didn't make mistakes in calculation, or if they did make mistakes, they would have been able to identify where they were). Instead, we all calculated many different x velocities and ended up just picking one of them due to lack of time. The one we chose happened to be incorrect. 

In order to solve the problem, we needed to determine the initial velocity of the ball when shot by the launcher. In order to do that, we measured the angle at which the launcher was pointed, which was about 6 degrees above the horizontal. We then used a stop watch and took a slow motion video of the ball being shot to measure the time the ball was in the air. This was one calculation that varied between class mates; we all used different times in our calculations which gave us a wide range of horizontal velocities. Then, we measured the horizontal distance which we did agree upon. The horizontal velocity was calculated by doing horizontal distance divided by time. From there, we measured the height of the projectile from the floor and used that height, the acceleration due to gravity, and the time in order to find the vertical velocity. Here was where our calculations were incorrect. We calculated the vertical velocity incorrectly because we made the y displacement positive and the acceleration due to gravity negative, even though they were in the same direction. Therefore, vector direction was our biggest fault in determining the initial velocity.

I did the problem again using the same measurements but designating down as positive and up as negative and keeping the direction consistent. Then, I calculated that the initial velocity to be 4.68 m/s. When using this as the initial velocity and using -4 degrees from the horizontal as the angle for the second scenario, I calculated that the horizontal distance should have been 1.997 m. Images of my calculations are attached below.

I am a senior at Irondequoit High School this year. I am particularly interested in Music, specifically playing the saxophone. I also enjoy playing sports, like soccer, basketball, golf, spikeball, tennis. I am a triplet, and have a total of 6 siblings, all of whom I am very close with. My strengths as a student are that I consistently work hard and complete things on time, and that math and science come naturally somewhat easy to me. I love working through math problems and being able to piece together what's given in order to create a meaningful solution. . I would like to attend Cornell University's College of Engineering next fall, with a major in Mechanical Engineering and a minor in Music. Two potential career goals of mine are that I would either like to work for Apple or I would like to work on making automobiles more environmentally efficient. 

I love problem solving, and I'm excited to do as much of that as possible while taking AP Physics C this year. I chose to take this course to better understand the world around and to understand physics as it relates to calculus. I hope to gain college credit for my AP scores in this class, to build new friendships, and to acquire a nearly complete understanding of the concepts taught in the course, and see how they relate to my interest in mechanical engineering. I am most excited about learning how calculus can be used to solve physics problems that I learned how to solve algebraically in Physics 1 and about completing labs to see the concepts that I learn are verified in the real world. I am anxious about E&M because the concepts of electromagnetism are difficult for me to visualize and understand. I am also anxious about the fact that my teacher does not lecture in class, that instead in order to learn I need to watch videos on Educator.com, which is something very new to me. I hope that I can understand the concepts well enough based on the videos. 

Overall, I'm excited about what I will learn this year!