# ZZ

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4. ## Ping Pong Physics

This past Halloweekend, I enjoyed playing a game of ping pong (or table tennis for you nomenclature inclined folks) with one of my fellow compadres, despite the result not ending in my favor. While some might dispute my strategies, claiming them as "unorthodox," I consider them successful for the most part and would definitely employ them to any worthy challenger. However, I will just do a basic overview on the physics that came to mind the other day when I was playing. First and foremost, Newton's First Law: an object in motion stays in motion, has obvious pertinence to the game itself. Once the ball ball is put in play, it will continue to move with a certain velocity, until acted upon by an unbalanced force (i.e. the opponent, air resistance/friction, or the table). Newton's second law gives us the relationship between net force, mass, and acceleration of an object. Since F = ma, we know that when a player exerts a larger force onto the ping pong ball, the ball will have a larger acceleration in its path of travel, and this leads to it being such a fast paced game. The last of Newton's Laws explaining motion - "For every action, there is an equal and opposite reaction" - would seem to apply as well, even though it is not very apparent through observation. Since the player hits the ball with the paddle giving it a force, the ping pong ball exerts the same force back. However, because the player and the paddle have much more mass, they don't experience the same acceleration as the ball. Lastly, Inertia plays its role as well by determining the maneuverability of the ball. Since inertia is a measure of mass, and the ball has a low mass, this allows each player to change the direction of the ball much easier than in most other sports, like tennis. Clearly, although it's nice to know all this physics stuff, it doesn't exactly help you win in ping pong... If you want to see a cool rally check this out https://youtu.be/LOynR3gj8rE
5. ## Leaf Blowing (Pt. 2 - C.O.G.)

In my last post I discussed the physics of leaf blowing, in the theme of the fall season we are experiencing currently. This weekend, while I continued the struggle of doing leaves at our foliage ridden house, I had to blow off the roof and clean the gutters using the leaf blower. While I'm not afraid of heights like some people are, I do realize the danger of being 20-30ft above the ground on a surface sloped toward my certain demise. In addition to the force I feel down the slope, which we know is mgsinø, I also had to account for the force of the leaf blower which I was using to blow the leaves up and over the roof. While I knew this would not be the safest method to blow leaves off, since I would have the force of the leaf blower and the force due to gravity pushing me toward the end of the roof, I did it anyways so that the leaves would end up in the forest behind the house. However, out of instinct, I made sure to crouch down low to achieve was most refer to as - a lower center of gravity. Center of gravity can be defined as the point at which we can consider the weight of an object to be concentrated. The lower one's center of gravity is, the higher its stability is. To increase my stability, I increased the area of the base supporting me by going down on all four. In addition to increasing the area of my base of support, lowering my center of gravity by crouching makes falling over more difficult. I managed to stay in what they call "stable equilibrium." An object in "stable equilibrium" will tilt and return to its original position, whereas an object in "unstable equilibrium" will tilt and then fall over. An example pertaining to center of gravity that most people can relate to is tipping over a coffee mug vs a tall dinner glass. Assuming the two have roughly the same mass and base area, why is it harder to tip over the coffee mug? It's because the coffee mug has a lower center of gravity. If you were to tip both cups, the tall dinner glass's center of gravity would cross its base before the coffee mug would, hence why it has a higher center of gravity and is easier to tip over. This is why when we want to become more stable, we lower our center of gravity to avoid tumbling over. Luckily I finished the job well, and lived to tell the tale!
6. ## Tis' the season

Greetings Comrades, Fall has many seasonal activities that come with it. One of these that I find rather unpleasant is raking/blowing leaves, due to its apparent futile nature. This past weekend, since my dad purchased another leaf blower, we were both able to use one and cut the time in half nearly to do our house's leaves. However, using a leaf blower can be frustrating due to the forces of air resistance and wind, which take away a substantial amount of kinetic energy from the leaves. Even the highest power of leaf blowers only blow at speeds of 120m/s. So theoretically, if the leaf were in the air for 1 second, the leaf should go 120m (neglecting air resistance). In this instance, air resistance causes the leaf to only go maybe 12m. Not only is it frustrating to see more leaves falling where you just cleaned up, but the fact that the leaves only go a short distance makes it even worse. Part of the reason the leaf experiences so much resistance is due to its surface area. Air resistance is largely determined by the amount of air molecules an object collides with in its intended path of travel. For example, if you took a marble and a leaf (of equal mass) and dropped them from a height of 20m, the marble would hit the ground first every time. Why is this? After doing some intense research, I believe it's because the leaf is making more "collisions" with the air molecules which slow it down more than the marble. It would take more of these collisions for the marble to reach its terminal velocity due to a lower area of contact, whereas the leaf reaches its fairly quickly. Th leaf's shape essentially causes it to be displaced less by the impulse from the leaf blower. Looks like I'll have more time to ponder such thoughts in the future, as my lawn is coated in leaves currently.
7. ## Adverse Weather's Effect on Soccer

As we near the end of October where most of the inclement weather begins, I'm starting feel the effects of it during our team's games. Recently, we have had games where wind has been a big factor. Wind, a form of kinetic energy, has a massive influence on the way each team must play the game. For example, if you have the wind at your back, you can take shots from further out, because the ball will experience less of a resistive net force against its path of travel while in the air - thus giving the ball a greater velocity in the x-direction. However, if your team has the wind going against you, you might not that longer shots because the wind increases the net force on the ball against its path of travel. If you had to kick the ball iin the air for some reason, it would be smartest to keep it low and hard, since the longer it is in the air, the larger the impulse felt by the ball is. In addition to the factor of wind, the moisture of the grass/turf from rain (and in a month's time: snow) is another aspect to be aware of. The wetness of the pitch conditions lowers the coefficient of friction on the ball. thus increasing the net force in the direction of travel of the ball when it is hit with a force. For a field player, this means that on a wet day, you must be a half-second on top of things because you will have less time to react to the path of the ball. You also know that you can take advantage of these conditions when shooting, and keep your shots low. If you're lucky, you can skip a shot off the ground and the goalkeeper will not be able to react in time, due to the decrease in the fricitonal force felt by the ball. As sectionals approach, these conditions will most likely play a large role in the flow of the game, since the weather at this time of the year is rarely ideal for such activities.
8. ## First Blog Assignment

Good looks Lessard
9. ## Blog Numero Uno

Alike my compatriots, this blog opens a year-long voyage through real life physics applications. I guess a good place to start my introduction would be what I do other than school (which could begin to exponentially decay in the upcoming weeks =) ). I thoroughly enjoy participating athletic activities, including Soccer, CYO Basketball, and the occasional round of Golf - even though I am utter garbage at it. I enjoy dressing well and have been told my shoe game is fire, however my friends don't like it when I wear a turtleneck. Also, if you can make a Spongebob reference in any given situation, we might be able to make things work as friends. I have several strengths in school but have just as many weaknesses; one of these could be my tendency to procrastinate (this blog post being Exhibit A). I have an older sister, Hannah, who currently is a Junior in college at MIT. I have very little idea pertaining to where I would like to attend for higher learning after high school, however I would like to pursue a career in math and/or science - thus influencing me to undertake Physics C along with BC Calculus and AP Chemistry this year. I'm well aware of the self-induced stress and pain that this means but I'm not one to turn down a challenge. Also, Physics with Mr. Powlin last year was pretty chill, so I really wanted to keep going on this tract. Through this course, not only do I hope to better my questionable time management and organization, but I hope to extend my knowledge of Physics to give me an edge when I get into college. I think the idea that you can determine the pace at which you go through the content is both a perk and a pitfall, and I hope I can learn to use it to my advantage this year, as well as use the online lectures to aid me in my endeavors this year. That is about all that I think anyone should know about me for now, godspeed fellow fizziks nerds. Looking forward to hearing about your futurenanigans and wise words.
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