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jrv12

Physics of Fetch

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A dog trying to catch a ball in its mouth is like a person trying to catch a football, a lot of coordination and timing. Kinematics could be involved to find the distance, but there is not enough time for a dog or person to calculate that since it only takes a couple seconds for the ball to reach the dog. However, if you ever did want to find the distance, you would need both the x and y components of the initial velocity, acceleration in the y which is equal to 9.8 m/s2, and the time it takes for the ball to reach the dog. It would be a little more complicated than a simple kinematics problem since there is the height of both the person and the dog to take into account.

When I was in Target the other day, I saw a new toy called the Chuckit which is basically just an extension of someone's arm that you can put a tennis ball in in order to throw it farther.

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Using the equation torque=Force*radius, the Chuckit increases the length of someone's arm and therefore the radius. By applying the same amount of force, the person can throw the ball much farther by using the Chuckit because of the increase in torque. So, if your dog isn't getting enough exercise from you just throwing the ball, add more length to your arm to throw it farther!

jrv12

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I'm sure everyone has heard the myth that if a penny is dropped off the Empire State Building it could kill someone. Well, fortunately you can still walk in NYC without shielding your head from falling pennies because this is not true. The penny will tumble as it falls which will slow it down, and because pennies are flat and thin, they experience a lot of air resistance opposing the force of gravity. A penny would reach a  terminal velocity of a meager 25 mph at 50 feet. Instead of going straight into your head like most people believe, the penny would bounce right off and you would most likely only feel a small sting. If air resistance didn't exist, the penny would reach 208 mph by the time it reaches the ground, which could definitely do some damage.

However, don't go walking around without your head covered just yet. A pen that is dropped perfectly vertical from the skyscraper would reach a terminal velocity of 200 mph, and would most likely kill you. Because of the narrow, cylindrical shape of the pen, it would fall like an arrow and pierce your skull, killing you. Now, if you're like me, you will want to walk around with a helmet on for the rest of your life in order to avoid a hole in your skull from a stray pen!

jrv12

While the once popular cell phone app reached its peak a couple of years ago, Angry Birds is a great example of projectile motion. The basic goal of the game is to launch the birds using a slingshot to knock out the green pigs. In order to knock out the pigs with the least amount of shots, you need to launch the birds with the correct initial velocity and at the correct angle. There are multiple different birds that are used in each level, including the standard red bird, a blue bird that turns into 3 birds when tapped, a yellow bird that changes to a faster velocity when tapped, a white bird that shoots down an egg when tapped, a black bird that blows up when tapped, and a green bird that turns into a boomerang when tapped. If we only look at the standard red bird, we can infer that the app does not take into account air resistance since the bird follows a parabolic path. Therefore, the horizontal component of the velocity stays the same and the vertical component of the velocity changes because of the acceleration due to gravity. The kinematics equations vf=vi+at , x=vit+1/2at2 , and vf2=vi2+2ax can be used to solve for the distance the bird will travel both vertically and horizontally using given variables. In order to cause the greatest damage, it is best to pull the slingshot back as far as it will go in order to have the greatest initial velocity and travel the greatest distance. Now playing Angry Birds should be much easier considering the projectile motion we have learned and how to calculate the correct initial velocity at the right angle in order to get the bird to travel the correct distance! While you most likely won't do any actual calculations, your estimations should be much closer and will hopefully help you get a higher score!

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jrv12

Put simply, the answer to this question is yes. But here's how I found out:

The other day, I was playing pool in my basement with my brother and, of course, I was looking at something on my phone just as the cue ball was hitting the 9-ball and he applied so much force that the 9-ball bounced off the table and landed right on my foot. It hurt really bad and I still have a large bruise right on the top of my foot.

Well, since a standard billiard table is .762m and we can use acceleration as 10m/s2 and the billiard ball started from rest from the top of the table, the final velocity that the ball hit my foot with was 3.9m/s. Ouch. A billiard ball's mass is .17kg, so the force that it hit my foot with was 17N. Ouch. Needless to say there is a large bump on my foot from the ball and now I will always pay attention the playing pool with my brother since he clearly doesn't understand physics well enough to be able to hit the ball with enough force that it will still move, but not too much force so that the ball won't end up on the ground.:hocky:

jrv12

The first point of sectional finals, we have serve. Ace. A couple more aces and a big serving run and we are now up 18-3. We end up winning the first set 25-6. 25-6. 25-6, in sectional finals, against Pittsford Sutherland. It is clear now who has the momentum moving forward. 

The momentum from the first set carried us in the next two sets and we end up winning the match and sectional finals.

In a sport, when a team has the "momentum" in the game, it means that they are the ones on the move and will be hard to slow down and stop.

In physics, momentum is the product of mass and velocity, and the equation is p=mv. Therefore, as mass or velocity increases, so does momentum. Momentum is also a vector quantity, so it has a direction to go along with the magnitude. A change in momentum is the impulse which uses the equation J=Ft. It would take a large amount of force in a large time to create a big impulse or change in momentum. Last night, Sutherland started to create an impulse in the second and third set, but it wasn't enough to sway the momentum in their direction.

Here's a video of the final point of the match last night!

 

jrv12

Most people have made oobleck at some point in their school career, whether it was in elementary school as a fun project or in high school to demonstrate physical properties.  

How did oobleck get its name? From the Dr. Seuss book Bartholomew and the Oobleck

This simple, non-Newtonian fluid made from a mix of cornstarch and water defies Newton's Law of Viscosity. Oobleck magically transforms (well, not magically, but it seems like it!) from a liquid to a solid with the slap of a hand, punch of a fist, or kick of a foot. Because of the shear-thickening behavior of oobleck, a greater applied force leads to a greater resisting force from the fluid and it behaving like a solid. Without an applied force, the oobleck will behave like a liquid. The behaviors of these shear-thickening fluids allow them to be used as body armor since they offer great flexibility and ease of movement, but would resist a sudden force such as a bullet or knife.

Watch this video if you've ever wondered how to walk on a liquid:

 

jrv12

Anyone who knows me well knows that I’m a very competitive person and I love to play ping pong. I have a ping pong table in my basement and my friends and I used to have tournaments and we even had a rule where if one person got a shutout against someone else, the person that lost would have to pay them $5 (this never actually happened because we would never go along with the rule if it did, it was just a joke we had). It also amazes me to watch table tennis on TV during the Olympics because they hit the ball so hard that I never knew how the person returning it doesn’t hit it off the table every time.

Well, it turns out that this has to do with Newton’s first law, an object in motion will remain in motion unless acted on by an external force, and Newton’s third law, for every action there is an equal and opposite reaction. When the person serving hits the ball, the applied force is so great that the returner doesn’t have to add any force to the ball (neglecting air resistance) since the ball hits the paddle with the same force it started with and the action of the ball hitting the paddle causes the ball to change direction. However, air resistance is an external force acting on the ball causing it to slow down, so the player should plan to hit the ball with a small amount of force each time. The force of gravity causes the ball to hit the table on the opposing player’s side, therefore keeping the game in play until one player adds too much force, too little force, or misdirects the ball so that the ball goes off the table or into the net.

Here's a cool video of the best table tennis point ever:

 

jrv12

Video 1

a.    4 beliefs that make people stupid:

·      Learning is fast

·      Knowledge is composed of isolated facts

·      Being good at a subject is inborn talent

·      I’m good at multitasking

b.   I tend to try to multitask while doing homework by checking my phone every once and a while, but then I have to go back and reread so in the end it actually takes longer

c.    Metacognition: A student’s awareness of their level of understanding of a topic

 

Video 2

a.    Most important factor in successful learning: what you think about while studying

b.   Deep processing: matching new information with already learned information and comparing and contrasting the two

c.    4 items that help learning:

·      minimizing distractions – don’t have my phone right next to me while trying to do homework

·      developing accurate metacognition – don’t overestimate the amount of material that I actually know and instead take the time to learn what I don’t know

·      deep processing of critical concepts – don’t just skim through something just to get it done and instead relate it to something I already know

·      practicing retrieval and application – quiz myself on the new material after I have finished learning it

 

Video 3

a.    6 aspects of optimizing learning:

·      elaboration – relate this concept to other concepts not only taking notes on the one video but relating it to things learned in other videos

·      distinctiveness – prove how this concept is different from other concepts by knowing the difference between integrals and derivatives

·      personal – relate this concept to personal experiences by forming the weekly blog posts on something I find interesting

·      retrieval and application – use and apply this concept within the weekly blog posts and webassign

·      automaticity – practice information so it occurs without conscious effort by writing equations without having to look at the reference table

·      overlearning – study beyond just knowing information so it can be recalled quickly by looking over notes again before answering questions so I don’t have to constantly look back at them

 

Video 4

a.    6 questions from the video:

·      What is metacognition?

  • A student’s awareness of their understanding of a topic

·      How did the teacher test for metacognition?

  • The teacher created a graph of the grades the students thought they would get vs. the grade they actually received and it showed that most students have poor metacognition

·      How does poor metacognition hurt academic success?

  • You might overestimate how well you know something and then get a bad grade

·      Why would metacognition that was good in high school be bad in college?

  • In college you have to apply knowledge to situations, whereas in high school you are mostly memorizing facts

·      What are the central differences between deep and shallow processing?

  • Deep processing is applying and relating information to something already learned, shallow processing is merely memorization

·      Name a task you already do where you automatically use deep processing?

  • Reading and annotating a book

b.   In video lessons, it is hard to write down everything the instructor is saying word for word, so instead it is better to listen and then summarize what was said with an example to recall for later use. Taking notes on the video engages you by intently listening and processing what is being said in order to fully understand the content. It is also important to create sections and title the notes so that you know exactly where to go back and look for a certain topic.

c.    A study group would obviously be of use in this class and most classes because others can help you learn information you don’t know and sometimes teaching is one of the best ways to learn!

 

Video 5

a.    What to avoid if an exam goes poorly: panicking and going into denial

b.   What to do if an exam goes poorly: examine how you prepared, review the exam, talk with the teacher, examine your study habits and if they are effective, and develop a plan for the next exam

c.    Helpful strategies to raise your grade: commit time and effort, minimize distractions, attend class, set realistic goals, don’t begin to slide or slack off, and don’t give away points

jrv12

All About Me

Other than being a student at IHS, most of my free time is consumed by playing volleyball. I also make time somewhere in my busy day to do homework and sleep. I don't know where I want to go to college yet, however I am planning on a major involving cybersecurity/digital forensics and I'm also interested in engineering, which is one of the reasons why I decided to take AP Physics C this year. I also wanted to take physics again because I like both science and math and this class involves both of them. This year, I am excited to continue learning about physics and applying it to real life situations because this is one of the only classes where that applies. However, I'm nervous about trying to wrap my head around some of the theories again this year because I had trouble with that last year. I'm hoping to have a great year with a challenging but intriguing physics class!

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