Physics of *Sports?*
- Evidence of Work
For this project, our group focused on conservation of momentum and analyzing it something that is not considered to be a traditional sport. Our group focused on air hockey since there was an air hockey table in the back of the classroom. One of the main reasons we chose this was the fact that our group thought that air hockey is mostly frictionless since air pushes up on the pucks which gives the pucks a near constant velocity. One other reason we chose this "sport" was the fact that the air hockey table had evenly spaced holes all around the table which would make it easy to record a video and find the average velocities of the pucks at different points. Our initial trial had us hitting two pucks against each other except that one puck was weighted with two pennies taped to the top of it and the other was unweighted. Our second collision was an unweighted puck traveling into a stationary weighted puck. Our third collision was essentially the same as the second trial, but this time, to reduce our margin of error, we placed two meter sticks to control their motion since the air would push the pucks in the "upward" and "downward" direction.
2. Content
Kinetic Energy: Energy from motion of an object. We calculated this using the average velocity and mass of the puck.
Thermal Energy: Thermal energy is non-mechanical energy that can be created from a force of friction which is created when two objects. When the puck was on the hockey table, it experienced friction since the force of the air pushing up on the puck didn't negate the friction force of the table and the puck.
Conservation of Momentum: In a closed system, momentum is always conserved. A closed system is where no outside force is applied to the object in the system. We used the average velocities of the pucks to prove that momentum is always conserved in a closed system. Conservation of momentum is calculated using m * v + M * V = m * v + M * V where the left side of the equation is the initial condition and the right side is the final condition.
Impulse / Change in Momentum: Momentum is conserved until an outside force acts on the system which is called an impulse. Impulse is calculated by multiplying the force by the time the force is applied. Impulse is equal to the change in momentum of a system which can be calculated by multiplying the mass of the object by the change in velocity. These two values can be set equal to each other. While our group did not use this concept in our project, it was an extremely important concept to the momentum unit.
3. Reflection
Our group was able to solve problems very well on this project since we encountered many problems that we were able to work around. For example, our initial thought that a air hockey table was essentially a frictionless surface was incorrect since the air hockey table we used had one fan blowing air to the whole table which resulted in an uneven distribution of air throughout the table. This became an issue when we saw that the pucks were being pushed by the air in opposite directions to our initial push so to fix this, we put meter sticks on the table to control the motion to the best of our ability. This gave us our most consistent data yet in video 3. I think that the presentation that I made was really well done. I was able to fit all of the necessary information in a clear and concise way without making the slideshow feel overwhelming. I included all of the necessary calculations and graphs to help prove that while momentum is always conserved in a closed system, kinetic energy isn't unless the collision is fully elastic.
However, collaboration was lacking in this project. I attempted to engage my group in this project but most of the time I found myself doing all of the work for the project. I did most, if not all, of the calculations along with most of the presentation. I feel as if I am partially responsible for this since I wasn't able to slow down and try to explain the concepts to my group members since I think they didn't understand the material at certain points. So in the future, I will have better communication with my group members in order to have better collaboration.