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MrMuffinMan

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  1. MrMuffinMan

    Maxwell's equations

    By MrMuffinMan,

    Gauss's Law

    Gauss's other Law
    Faraday's Law
    Ampere's Law

    We've already done the first one which isn't that bad and I hope they're all that simple. Although I think the second one means magnetic field though a closed surface is 0. And Faraday's law means something with E field is equal to the rate of change of magnetic flux. And i have no idea what Ampere's law is saying.
  2. MrMuffinMan

    Solar Sails

    By MrMuffinMan,

    Currently the only way for us to get around in space is to use rocket fuel and chemical reactions to push the rocket around. This is very expensive and current rockets are 95% fuel by weight. However NASA is developing an alternative that uses the the sun to push the rocket around. These solar sails are made with large ultra-thin mirrors that use the light of the sun to push the sail around. These sails have to be reflective because when the light hits the said it has to be reflected. This they key because thanks to DeBroglie, we know that light has momentum and as the light changes direction it exerts an impulse on the said which accelerates the sail. Granted this force is tiny compared to rocket engines, but in space the the sail will accelerate as long as it sees sunlight which means it can go much farther without fuel on board.
  3. MrMuffinMan
    A bottle rocket works because of Newton's third law of motion. As more air is pumped into the "tank" the pressure increases so that when the restraint holding the rocket in place is removed, the pressurized air forces the water out of the bottle. Newton's third law states that for every action there is an equal and opposite reaction. This means that water exerts an upward force on the bottle itself. This is what sends it into the air. A nose cone works by cutting through the air instead of the blunt bottom of the bottle forcing itself through the air which would increase drag. Fins help by stabilize the flight via air flowing over them helping keep them and the rocket in line. Finally the parachute works by increasing the drag force caused by air so much that it slows the rocket down to a speed safe for landing
  4. MrMuffinMan
    The most important technology that came out of WWII was the nuclear bomb. But the second most important technology and probably the most used today is Radar. Every airport in the US uses Radar to track flights. But the physics behind this technology is very simple. It's the Doppler effect. A Radar system has two parts a transmitter and a receiver. The transmitter sends out a burst of radio waves. These waves go until it hits an object, say a plane and bounce back with a different frequency because due to the Doppler effect a plane moving would cause the waves to bounce back faster or slower depending on the direction of the plane in regards to the transmitter. Then the receiver detects the frequency of the returning waves. Using the equation f'=fo(c+vplane)/c where c is the speed of the waves in air, the Radar computer can determine the speed of the plane. Also the computer can find the location of the plane by using the difference in time from when the waves were sent to when the waves were detected by using D=2Ct since the time is for the waves to get there and back.

  5. MrMuffinMan
    Real rockets work just the same as the model bottle rockets that we made for arts fest. Rocket engines instead of using water expel gases and the pressure that is used to expel these gases come from the burning of fuel.When the fuel is burn, the energy released increases the temperature of the gases that created when this fuel is spent. These super heated gases want to expand which causes the pressure to increase. As the pressure increases, the gases are pushed out the back end of the engine which because of Newton's third law of motion also push the rocket engine and everything attached to it in the opposite direction.
  6. MrMuffinMan
    With our last test we finished mechanics and official ended the first halve of the year. Surprising I didn't find the course as hard as I thought it was going to be. AP-B last year taught us most of the basics so we already knew most of the physics that we used this year. The major difference this year was the addition of calculus which isn't terribly hard compared to what Mr. Muz gives us. Also this year we aren't just given most of the equations and told to memorize; we are shown how to derive them and then expected to know the derivation as well as the equation. I'm a little afraid of Electricity and Magnetism because mechanics were easy to visualize which makes understanding easier for me, but when we're talking about tiny electrons, it's not so easy to picture. But hopefully it won't be too bad.
  7. MrMuffinMan
    March has always been the worst month of the school year and this was no exception. A combination of harder classes, more homework, sports and the increasing effectiveness of seniorities turned the last week of the 3rd quarter into a cram session of trying to get everything done. Seeing how I am doing these blogs, it's clear how far behind I was and still am. This has been a rude awakening as to how much stress procrastination causes and I hope that I will be able to put off seniorities until after AP
  8. MrMuffinMan
    Released in 1984 Tetris has been confounding physicists as to how the blocks move in the way they do. Now almost 30 years later, the secrets of tetris have final revealed. The blocks are moved using a combination of magnetism and electricity to move the block sideways and down. Unseen to the player each block has a slight positive charge and at the bottom of the screen there is eletric plate that is negatively charged. This causes the block to accelerate downward but it is only on for a few milliseconds before it's turned off in order to keep the block at a constant velocity. As the game goes on, the plate is left charged for longer which means the block reaches a faster speed. When the player presses the down button, the plate becomes negative charged again, causing the block to accelerate again. In order to move the block left and right, when the player press the left or right buttons the game creates a magnetic field. Since the blocks have a velocity downward, the magnetic field exerts a force on the block to the left or right. For example when the play press the right button, the game creates a magnetic field into the screen and by the right hand rule, the block feels a force to the right. And when the player presses left, it creates a magnetic field out of the screen which sends the block to the left. In order to turn a block, the game has to create two magnetic fields in opposite directions(one in, one out) that split the block in half(top and bottom). This creates a torque on the block that causes it rotate. Finally once a row has been filled, it completes a circuit that now has a current running though it. Behind the screen, there is a wire carrying current in the same direction and since wires carrying current in the same direction attract, the row is sucked behind the screen leaving space for the remaining blocks to slide down. Tetris may seem like it defies most laws of physics but we can see that it has to follow the same rules as all of us.
  9. MrMuffinMan
    Today is a beautiful day for a hurricane and since we have no school we all get to sit home and watch the hurricane bear down us on the radar. Looking at the Google earth we can all see that Sandy looks like a giant cloud with a hole in the middle that is spinning counter clockwise. But why? The answer is the Coriolis effect. Now what the heck is that? "In physics, the Coriolis effect is a deflection of moving objects when they are viewed in a rotating reference frame." This is saying that an object traveling "straight" like winds, on something that is rotating, such as the earth appear to curve when looking from the earth. So the Coriolis effect causes winds to deflect to the right in the Northern Hemisphere and left in the Southern. So when a low pressure system forms in the Northern Hemisphere, and air rushes to fill the area, the winds deflect to the right and cause the counter-clockwise motion to start

  10. MrMuffinMan

    Physics of Tennis

    By MrMuffinMan,

    The sport of tennis is the oldest and most love sport in the world. People have been playing tennis ever since the Acient Greeks took a stone and started hitting it back and forth over a fallen tree with branchs. Granted back then the sport was much more dangerous; many an acient greek lost an eye or a limb due to getting hit with the sharp rock that they played with, but even today the physics that govern the game today with the tennis balls with fuzz that sticks to your socks remain the same. Tennis is all about redirection of energy. A ball bouncing off the ground is effected by an impulse that changes the direction of it''s velocity. Current tennis balls are usually so bouncy that the collide elastically with the ground which means there's no loss in energy or speed. Then when the player hits the ball, the player usually swings the racket(or tree branch) which absorbs some the the energy so when the player hits teh ball some of the energy is lost but the ball gains more energy coming off the racket because it gains energy from the racket that has it's own energy that is transfered to the ball. Top spin on the ball causes it to go down because relative to the ground, the top of the ball is moving faster than the bottom so, air is flowing over the top faster, which causes the air to exert a force on the ball downward.
  11. MrMuffinMan
    This again come from MindCipher.com.

    A person is holding on to a helium balloon in an elevator. The elevator cable snaps, and at the exact same moment, the person lets go of the helium balloon. In the perspective of the person in the elevator, what happens to the balloon the moment the cable snaps?
  12. MrMuffinMan

    10

    By MrMuffinMan,

    Time to finish this. And This is just going to be all about how i feel the class is going so far. Right now I enjoy this class because it's not extremely hard. Yes the tests are hard but we're not learning anything new were just using derivatives and integrals on equations we used last year. I think the reason we think the tests are so hard is because we're not always taught everything that's going to be on the test and Mr. Fullerton leaves some stuff for us to figure out; which wouldn't be to bad except we don't always have enough time during the test to work through the problem and discover the trick. Like i remember on one test, we had to figure out an equation for the horizontal distance a projectile was going to travel given only the vo and the angle. When i got to this question i just when oh **** and moved on which is what most people i assume did. But going back and looking at it later i realized that it wasn't too bad because we could solve for time in the air and multiply it by the velocity in the x direction. But also there was a trick that you had to remember that 2sin(x)cos(x)=sin(2x) which i feel like would of thrown a lot of people off if they got to that point and didn't remember. I hope that as the year goes on I will be able to see things like that faster and be able to work my way through problems the likes of which i have never seen before.
  13. MrMuffinMan

    Free falling

    By MrMuffinMan,

    Afraid of heights? Well this guy isn't. Felix Baumgartner just made skydiving out of a plane look like a joke. In case you haven't heard because you don't get service or internet under the rock you live beneath, Felix just jumped out of a balloon 128,100 feet above the ground. Yeah that's over 24 miles. He also broke the world record for the fastest skydiver; reaching a velocity of 833.9 mph, faster than the speed of sound. I guess I have to talk about the physics behind this crazy stunt. If we look at it like we would of last year, neglecting air Resistance, vf2=vo2+2ax and in this case a is 32 ft/sec2 so if there was nor air he would be falling at 2863 ft/sec or 1952 mph or Mach 2.5 and I don't even need to know about impulse or momentum to be able to say for certain that's instant death. Plus if there's no air resistance, there's nothing to slow him down when he opens his parachute .Also it would only take him 89 seconds to fall that distance instead of the 4 minutes and 20 seconds. But since he didn't reach that speed and go splat against the ground, we can assume that there was air resistance on this day. Remembering the equation that we were "taught" in class F=bv and bvt=mg and since I don't know Felix on that level, I didn't feel comfortable asking he weight so we'll just have to use the average mass of an adult(175lb) to get b at about 4.6 lb/sec(gotta remember convert 833mph to 1223ft/sec). Of course there is error in all this because acceleration due to gravity isn't exactly 32 ft/sec2 24 miles above the earth surface and the force of air resistance increases as he gets close to the earth and the density of air increases but that requires a lot more information then i could find.
    http://www.bbc.co.uk/news/science-environment-19943590
  14. MrMuffinMan

    How Bullets fly

    By MrMuffinMan,

    Skipping the intro, bullets gain all of their kinetic energy from expanding gas. When the trigger is pulled, the firing pin in the gun comes forward and ignites the gun powder in the shell. The chemical energy stored in the powder is then convert into heat which cause the temperature of the the air between the bullet and the shell to rise rapidly. Remembering the equation from last year PV/T=PV/T this shows that when the temperature increases ether the pressure or volume has to increase also. In this case, the first thing to increase is the Pressure and this increase pressure creates a force on the bullet that sends in flying out of the barrel. All of this happens in a fraction of a second.
  15. MrMuffinMan
    Were as the idea for planes and the physics behind them make sense, the helicopter is completely different. In order to create the same lift as a plane does by getting air pass over the wings very fast, a helicopter has to lift by spinning it's rotor blades very fast. the same principle of fluid dynamics is responsible for the lift force on a helicopter. The blades on a helicopter are shaped almost the exact same as plane wing so that when they are spun they create a upward force on the helicopter. All the blades together spinning create a small low pressure system above the blades and the air below pushes up. However since the helicopter is in the air, they is no force to stop the cabin of the helicopter from being spun the other way which is why almost all helicopters have the tail rotor which uses the same physics to create a force that keeps the fuselage from spinning. Using physics we have been able to conquer the sky.

  16. MrMuffinMan
    In today's world we've almost all been on a plane at least once in our lives but it was just over a hundred years that the Wright brothers flew for the first time. The physics behind flight is not very complex at all but most people don't think about what's keeping them from dropping 30,000 feet in a 490 ton airplane. In the follow picture we see the all the forces acting on the plane and we all know that for the plane not to fall from the sky the net force in the up direction has to equal 0 so the lift has to be greater than the weight of the plane. But what causes lift? Fluid Dynamics. Even though air isn't a liquid it's still a classified as a fluid and follow the same rules. According to Bernoulli's Principle, faster flowing fluids exert less force than slower moving fluids. So when the air flows over the wing, it has to go further because of the shape of the wing so it goes faster and exerts less force than the air flowing underneath the wing. This creates a force up lift which is how a plane stays in the air.

  17. MrMuffinMan

    First post

    By MrMuffinMan,

    I'm going to start off with why I'm taking AP-C physics because I think that's the best place to start. But anyways I'm taking AP-C because i last year AP-B physics was one of my favorite classes and i really enjoyed learning how the world around us works. Also applying the things that we have been learning in math for the past four years is really rewarding because finally there's a reason to learn it instead of just because the teacher says we have to in order to past the final.

    I am the kind of person who is better at Math than English and i always like science but didn't really find it interesting until last year in AP-B. Also right now my career of choice is an engineer, I don't know what kind yet, but this class will teach me things that all engineers must know which is one of the reasons I signed up for this class.

    This year i want to continue to learn how the world works especially electricity and magnetism because I find those the two most interesting topics that we covered last year. Also I hope to have fun in in this class while learning the kind of math/physics that engineers use.

    I am most excited about being a senior because it's our last year of high school and we get to have fun.

    I am most anxious about applying and selecting a college because it's a long process and I hate making decisions and I can barely think about it. Maybe I'll just apply early decision.

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