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Showing content with the highest reputation on 05/03/2013 in all areas

  1. My childhood, like many others, was spent watching many Disney Movies. One of my all time favorites was the Lion King- I never grew tired of it. One scene that always sticks in my mind is that once music number of young Simba and Nala and, of course, the scene of Mufasa's Death. (0:49-1:20) It can usually bring tears to even the toughest of teens, yes? As a child, this scene really never bothered me and, now, this sad scene seems to bother me so much more. Mufasa died a heroic, and untimedly, death by saving his only son. However, we should move onto the Physics now. How accurate is Mufasa's death, exactly? Could a fall from that height really kill an adult male lion? How far did he fall, anyway? It's very hard to tell but, after reviewing this scene many times I feel I can give a good shot at answering these questions. From what I can tell, Mufasa's fall lasted roughly 5 seconds (1:07-1:12ish), and started from rest before... Scar decided to be a jerk and condemn Mufasa to death. So, using the equation d=vit+(1/2)at2, knowing his falling time was 5 seconds, he started from rest, and acceleration due to gravity is 9.81m/s2; It can be estimated that Simba's father fell about 123 meters. While he seemes to be fairly high before he fell, I highly doubt that the the distance (vaguely seen at 0:50) was taller than the Statue of Liberty. Obviously, it makes sense why a Disney movie would over exaggerate the death of a character, and not care about making the Physics of a children's movie accurate. While real Lions are tough and resiliant, a fall like Mufasa's (even if less than 123meters) would still kill or severely injure an adult lion- not taking into account the stampeeding wildebeasts trampling. So, as expected, Disney's The Lion King takes little care in being realistic... It was still interesting to think about, however! And imagine how cool (at least, I think so) it would be if a childhood classic was actually completely accurate- in a physics sense (because animal's can't talk).
    2 points
  2. <p>Longboarding is a particular hobby where a bunch of different physics topics are covered by a simple act that doesnt take much energy by the rider, but can still experience great thrills and excitement. Different keytopics with in this activity include, motion and forces, friction and energy.<br /> Motion and forces are key components of longboarding. The forces in particular enable the motion to take place. The force of gravity acts on the longboard and its rider. The greater the hill (incline) the greater the angle off the horizon and this allows gravity to have more of an effect as it acelerates you down the hill and increase your velocity. Also if your mass is greater, then you contribut more wieght where the force of gravity will be able to act on more matter and allow you to possess a greater degree of motion.&nbsp;</p> <p>Friction is another key component in a couple aspects. First off, in order to stay more secure with the board, rubber shoes are ideal because they create the greatest combination for the force of friction with the grip tape on top of the board. This force of friction is what helps reduce your chances of falling off the board and getting seriously injured. Also the other component of friction is between the wheels which are composed of a hard plastic and the pavement where friction is at a minimum to allow one to go fast and smoothly.&nbsp;</p> <p>Also momentum is another topic to discuss. In this activity one can achieve a fast forward momentum due to the length of the incline and also the angle of elevation from the horizontal. If both are optimum, then 30 40 even sometimes 50 miles an hour at some extremes is a whole lot of speed, and falling would hurt alot. Which brings us to impulse, (change in speed) and this is what we care about most for safety aspects. If its a quick difference in speed, (quick impulse), like hitting a rock and haulting the board, then one cant handle and or absorb the shock in a controlled fashion resulting with some extra momentum not being transfered through the board to a stop but instead its converted to access speed and results in one flying forward onto the ground. So we want soft easy change in speed where we can slowly come to a stop so avoid cracks and or rocks in the road or else.&nbsp;</p> <p>Lastly energy and this has to do with potential and kinetic energy. Potential energy is before you star where if you go on top of a large hill, you have potential to go down on the longboard and when you go, the energy is in turn transfered into kinetic energy and this is your forward motion.&nbsp;</p> <p>All these components are what make up the physics facts of longboarding.&nbsp;</p>
    1 point
  3. Last night I was at an awesome concert, but as I looked around, I realized how much physics can truly relate to everything going on around me. First of all, if you are at a concert, you expect to hear some music. That must mean that sound waves have to be traveling through the air for everyone to hear it. As I was sitting there enjoying the concert, I realized that the speed of sound in air at STP is 3.31x10^2 m/s! This made me extremely happy to have some background information on sound waves that most people don't have because they didn't take regents physics. I also knew that the closer I got to the stage, the higher the frequency and amplitude would be, and if I started heading towards the door, the amplitude and frequency would decrease, which illustrates the Doppler Effect. Also, there were some pretty awesome lights shining all over the stage and occasionally over the crowd. I was watching the colorful lights, when all of a sudden the electromagnetic spectrum came to mind. I thought about how out of the whole spectrum, there is only a small part that is made up of visible light. I also thought how all the colors can come together and if they are reflected, that creates white, and if they are absorbed, that creates black. I also realized how fast light must be traveling, at a speed of 3.00x10^8 m/s! This information gave the concert a whole new meaning. As I was looking around at the crowd, I noticed that a lot of people seemed to be crowd surfing, but many of them fell to the ground, which looked pretty painful. I then wondered what their final velocity would be when they hit the ground, so I decided to use one of my kinematics equations to figure it out. First of all, a person's initial velocity would be 0 m/s, because they are just lying on top of the crowd right before they fall. They would probably fall a distance of 2.5 meters, and their acceleration would be 9.81 m/s^2. I then could use the equation vf^2=vi^2+2ad, and once I plugged in all of my known values, I figured out that their final velocity would be about 7 m/s.
    1 point
  4. First let me warn you that I'm barely scratching at the surface of consciousness and the scientists still have a lot to learn. When you search this there seems to be two theories one that consciousness is similar to computers the other that consciousness revolves around the unity of different worlds and the reality as we see it is only an illusion. If you want to see a short clip of the physics of consciousness you can watch this: This only tells part of they story and other you tube videos can go on for a couple hours trying to explain consciousness. But one of the main points it brings up is that there is more in this world than by our human senses we can detect. Our bodies are made up of several worlds the one we see and can comprehend, the world of our cells and even smaller the world of the atoms that make up us. The world is made up of waves and somehow the world of intentions can change what goes on. One of the experiments that proved how your thoughts can change the way something turns out is an experimental machine that randomly generates coins of either 1's or 0's. They would tell people to try to count more ones than zeros and according to their results the number they thought about whether it was more ones than zeros or whatever would relate to the number of coins that the coin generator would produce. Another thing they talked about was how their is more than enough energy in the vacuum of space to produce universes. Yet we can't see anything but the vacuum can't be empty because of the continuation of stars being created out of seemingly nothing and the possibility that electrons can be both here and there and nowhere at the same time. Like Mr. Fullerton's cat in the box experimental theory he got from some other scientist trying to explain Quantum Physics. You would theoretically put a cat in the box with a capsule of cyanide that has a 50 percent chance of going off and killing the cat. Yet you couldn't see the cat or shake the box or the capsule would automatically go off. So you would assume the cat was both dead and alive like how with the double slot experiment with electrons you would assume it bounced of the background, went through both slits and also interfered with itself creating the interference pattern. So with the little I know and the information I learned from the video you can learn some interesting facts and concepts about consciousness that you might never have thought about before.
    1 point
  5. Thrilled to help, and welcome to the APlusPhtsics Community! The short version... The College Board says you need to know how to derive them. Very rarely have they asked students to do so, but it has happened... This guide sheet may help with studying: http://aplusphysics.com/courses/ap-c/tutorials/APC-Dynamics.pdf Good luck!
    1 point
  6. http://www.youtube.com/watch?v=a19fhhJcs1E Although a bit lengthly the significance of this video takes a tour of the life and death of starts and what they have to offer in the universe. Also, some facts about stars include that it is large celestial body composed of gravitationally contained hot gases emitting electromagnetic radiation, especially light, as a result of nuclear reactions inside the star. Stars are wondrous things that we know little about because of our limitations in technology. However, we learn more and more each day. they come in a variety of colors and sizes. Blue stars are hotter then white stars, white stars are hotter then yellow stars. Red stars are the coolest Ive always wondered what would happen if the sun completely blew up while humans are still alive to witness it
    1 point
  7. 11/10 already and all i've read was the title.
    1 point
  8. Soo are you saying that if we were to find enough energy we could travel through space?
    1 point
  9. If space travel was possible, could their be other planets that could sustain human life?
    1 point
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