Physics of *Sports*
Evidence of Work
For the fifth unit of my AP Physics class as a junior, we learned about collisions and momentum. Most importantly we studied the law of conservation of momentum, stating how momentum is always conserved in a closed system. The project we were tasked with this unit was focused on momentum throughout collisions of different objects. The main objective of the project was to analyze the difference between inelastic and elastic collisions, as well as learn how to calculate the percent of energy that was conserved during the collision. For this project we had to choose a video of a collision to analyze, and calculate the momentum of the objects before and after the collision.
As a group we decided we wanted to choose a more difficult video to analyze so that we could further challenge ourselves. The sections of video we chose were taken from a dude perfect archery trick shots video. We had to calculate both the kinetic energy as well as the momentum of an arrow being shot at a frisbee thrown in the air. This proved to be very difficult due to the fact that we had very little frame of reference for the distances between objects. However, we worked hard to think through the correct process of calculating this data and we even attempted answering a bonus question for this video specifically.
Physics
Velocity: Velocity is the rate of change of the position of an object with respect to time. The equation for velocity is: v = 𝚫d/𝚫t, or velocity equals the change in distance over time.
Acceleration: Acceleration is the rate of change of the velocity of an object with respect to time. The equation for acceleration is: a = 𝚫v/𝚫t, or the acceleration equals the change in velocity divided by the change in time.
Air resistance: Air resistance is the force of drag that acts against the direction of motion in the air. While we did not analyze the impact of air resistance on this collision it is a very important concept to know.
Momentum: Momentum is the tendency of moving objects to keep moving or in other words it is how hard it is to stop an object. The equation that represents momentum is: p = mv, or momentum equals mass times velocity. Momentum is always conserved in a closed system. We calculated the momentum of both the arrow being shot in the air and the frisbee being thrown in the air.
Collision: A collision is an event in which two or more bodies exert forces on each other in a relatively short time. there are two types of collisions: elastic and inelastic. No matter what type of collision, momentum is always conserved.
Inelastic Collision: An inelastic collision is a collision where there is a loss of kinetic energy to other forms of energy. Since it is impossible to have a perfectly elastic collision, an inelastic collision is usually defined as a collision with high amounts of kinetic energy being lost. The arrows hitting the frisbees in our video analysis were very inelastic collisions. The equation for an inelastic collision is: (mass 1 times velocity 1 initial) + (mass 2 times velocity 2 initial) is equal to (mass 1 + mass 2) times velocity final.
Elastic Collision: An elastic collision is a collision with no loss of kinetic energy to any other forms of energy. An ideal, perfectly elastic collision is actually impossible due to the fact that there will always be some percent of the kinetic energy lost to other forms of energy like heat. Due to this, an elastic collision is usually defined as a collision with a small percentage of kinetic energy being lost, like a bouncy ball being thrown against the wall. The equation for an elastic collision is: (mass 1 times velocity 1 initial) + (mass 2 times velocity 2 initial) is equal to (mass 1 times velocity 1 final) + (mass 2 times velocity 2 final).
Reflection
Through the entirety of this project my group had to really plan out our steps in analyzing the videos we had chosen and processing the correct calculations. I definitely improved my skills as a critical thinker, due to the fact that my group had decided to choose the more difficult video to analyze. In my opinion, I found it very beneficial to challenge ourselves while working through this project. This high amount of critical thinking also allowed us to collaborate very well together. We all shared our thoughts on how to work through very difficult problems, and came to decisions for the project as a team. While being a very difficult project, I enjoyed the challenge of trying to work out the correct process of calculating the physics of the arrow collision.
Due to the fact we really pushed ourselves to analyze more difficult videos in this project, we did not organize our time as well as we should have. We were so focused on making sure that we did our calculations correctly, that we left little time to work on our final presentation of all the great work we had done. This caused us to stress about finishing the presentation in time, which in hand caused us to rush the creation of our google slides. Although there were no real opportunities in this project to focus on cultural competence, it is a skill that I could improve on for any future stem projects.