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DavidStack last won the day on June 11 2013

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About DavidStack

  • Birthday 05/12/1995

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  1. DavidStack


    Cool stuff! It's awesome that you're getting introduced to this stuff even before college.
  2. Haha I like the 5 worsts... but this is good stuff! I really enjoyed this class as well, as difficult as it was.
  3. Great advice, I agree! However, I am not the biggest text book reader - I found that Mr. Fullerton's videos helped more.
  4. Hahaha well played Mr. Fullerton. But this is pretty interesting! I don't have a cat, but you can borrow one of my younger siblings I guess...
  5. It's pretty ironic that you posted on this right before Mr. Fullerton talked about it, but this is definitely curious!
  6. Oh Charlie, such a giver. But true, blog posts definitely help us learn better and aren't too bad of a hassle if you actually stay on top of them, which I was very good at failing to do.
  7. DavidStack

    the end

    I echo what Luke said. Kick some butt in college Joe. Show them how Irondequoit does physics!
  8. This is arguably the greatest blog post yet. You really captivated some interesting physics; I'm quite impressed.
  9. Well this is kind of bittersweet, finally being done with blog posts but also realizing that high school is completely over, as is Physics C with a fantastic teacher. I've learned so much during the year, from angular analogs to retarding forces to induction to the sheer brilliance of Walter Lewin's ability to draw a dotted line; it's been quite a year. I've appreciated this blog posts as much as I've hated them, mostly because they forced me to truly learn the stuff that I write about. And now when I struggle with physics in college, I'll always be able to go back to APlusPhysics and ask for help. I encourage anyone and everyone to take Physics C - it's certainly challenging but I can't see how you could regret it. So, farewell APlusPhysics, I'll likely come crawling back in no time at all.
  10. DavidStack

    Hot Rod

    Hot Rod, arguably the greatest movie ever created, actually has quite a bit of physics incorported into it. The part I will focus on is when Rod fails miserably to jump the local pool. Barely making it halfway, Rod slowly spins forward while in the air and lands face first, bike and all, into the pool. His demise results from two things - lack of kinetic energy and conservation of angular momentum. While he did have a ramp leading up to the jump, it was not nearly big enough to clear the pool. Thus, his moped could not gain enough speed, which meant that he didn't have enough kinetic energy to convert to potential energy to reach the height he needed to reach. Not only so, but while taking off the jump, Rod leaned forwards. Since he couldn't control his angular momentum while suspended in the air, that initial momentum continued while he was in the air, leading him to rotate forward ever so slowly and land on his face. All in all, Rod clearly didn't understand the physics needed to clear this jump. However, he made the movie hilarious, which is all that matters I guess.
  11. As I go off to Tufts University in the fall, one of the things that I'm looking most forward to is joining the qudditch team, where I will be a chaser. One of the tuft-est (see what I did there?) things about being a chaser is that one hand has to hold the broom while you run, meaning that you have to catch the ball with solely the other hand. This is difficult for two reasons: 1) The force felt from the ball is directed onto one hand instead of two, so the force is spead across a smaller plane, making it more difficult to control the force. And 2) With two hands you can catch the ball on its sides, forcing the ball to naturally slow down over a longer period of time, thus decreasing the force felt. But with one hand, you have to find a balance between securing the ball and moving your hand with the ball in order to increase the period of time of the ball slowing down. This is a tricky maneuver and can easily lead to one dropping the ball. So even though quidditch can be difficult, I'm very excited to play.
  12. 1) Don't worry about the time, it will just make you work slower. 2) If Mr. Fullerton says it's going to be on the AP, it's probably going to be on the AP. 3) Since the AP changes every year, test taking strategies can often come in handy more than trying to hammer in every single thing we ever learned in the entire year.
  13. So apparently there's more to dropping a ball than just gravity... who would have thought?! Well, for starters, when the ball is above the ground it has potential energy, due to the equation U = mgh. (See? Gravity is key!) As the ball comes closer and closer to the ground though, that potential energy is steadily converted to kinetic energy in the form of velocity (k = .5mv^2). Since m is in both equations, the mass of the object does not affect how fast the ball falls nor the time it takes the ball to fall. HOWEVER, an important thing we learned in Physics C this year is that not all of the potential energy is converted to kinetic energy, due to the fact that a drag force acts against the object falling. This drag force creates friction, which heats up the object, and that heat accounts for the "lost" energy. So that is the physics of dropping a ball, although, as I previously stated, it can really be summed up by this: gravity.
  14. There are a few things that come into the physics of punching something. First off, impulse plays a huge role in punching somehting. Obviously as you punch something such as a wall or a person you will experience an impulse as you have a change in momentum. Therefore the thing that you are punching will feel the force of the punch as well as the impulse delivered from the punch. Due to Newton's second law you, the puncher, will also feel a force driving backwards in your direction as every reaction has an equal and opposite reaction. This describes the physics of punching something with your fist.
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