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SJamison

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Blog Entries posted by SJamison

  1. SJamison

    A flexible pencil???

    By SJamison,

    Why does a pencil or any linear object look like it is bending when you wiggle it? I was very curious of this today and was wondering why? The answer to this question is that in the way you are wiggling it you are rotating around its center in such a way that our eyes perceive that the ends of the pencil is moving faster even though the angular velocity is truly the same through out because it is truly a rigid object. The reason for this is because when an eye is viewing a fast-moving object the formed image can be modeled as the image of points that appear to have different velocities on the same object. The reason our eyes do this is the same as when transitioning front light to dark. It takes time for our eyes to focus and adjust to our surroundings so by our eyes focusing on the fulcrum or our fingers in this case, it cases it ends to blur.
     
  2. SJamison

    And so it begins

    By SJamison,

    I'm really looking forward to this year in physics C. I really enjoyed AP physics last year and it sounds like this year we will be adding onto content that we previously learned which will be great. However, the class so far has seemed pretty terrifying, even though we have only been at it for about 6 days, the thousands of accounts to sign up for and the mountains of work hanging over our heads(which of course has potential to do damage hahaha) makes it look like we are in for a challenging year. But, I do think that with some strict time management and and staying on top of the work it will help to make it easier as we endeavor into the world of physics C. 
  3. SJamison

    Bullet proof glass

    By SJamison,

    Everyone calls it bullet proof glass but in reality nothing is bullet proof. The term for it is bullet resistant because if something is shot enough, one will find its way through eventually. Bullet resistance glass is a combination between very thin sheets of glass and even thinner sheets of tough plastic made of polycarbonate. This is able to work because as the bullet hits the glass it breaks the thin sheets of glass and the energy from the bullet is absorbed by the plastic layers. To make this effective you increase the number of layers to absorb more energy. The ratio between glass to plastic is normal 3:1 were the layers of plastic are 1-3 mm thick and the glass is 3-10 mm thick. This is crazy to think that by layering glass and plastic it is able to stop a .308 caliber marine sniper bullet, one that will knock you off your feet entirely.  In this video you can see that this glass is only successful for two shots from a .308 rifle at close range. So if you are in a car with a sniper shooting at you and have this glass between you and the bullet, I would suggest driving pretty fast. 
     
     
  4. SJamison

    Driving a car

    By SJamison,

    So my Friend Timmy C. is not the best driver.  See he has just stated and doesn't quite get that you cant hit the brakes really hard. So as you can imagine it is a very jerky car ride. And thinking more about this it is because of out mass that we will continue to move forward even though the car has slowed. This is because of inertia and mass is a property of inertia. Inertia is the resistance to acceleration based on mass. So therefore a heavier mass will be harder to accelerate and a lighter mass will be easy to accelerate. Applying this to the car situation above it is easy to understand why we continue to move forward the driver applies the brakes hard because you do not want to decelerate, having mass, so you continue to move forward. Here is an extreme example, caution this clip may be violent in some eyes.
     
  5. SJamison

    Dropping a gun

    By SJamison,

    In almost every action-comedy movie there is a person who happens to drop a gun and then it goes off. This however just does not happen every time a gun gets dropped. For a gun to be fired it requires the firing pin to be activated and to do so you either need to pull the trigger or get the hammer to release and come into contact with the firing pin. The chances of this happening are slim to none. In fact, a lot of gun instructors will tell you that it is safer to just drop the gun if it falls out of your hand rather than try and catch it. This is because well trying to catch the gun as it falls there is a good chance that you will grab the trigger in the process and discharge the weapon. Even though in all of the movies it looks super dangerous to drop a gun it really isn't as bad as what they make it out to be. However if you are dropping a gun I don't think it should have been in your hands in the first place. 
  6. SJamison

    Falling down the stairs

    By SJamison,

    So last night it was very late and dark and my mom decided to leave a basket at the top of the stairs. I think you can see where this is going from the title. So going down stairs was very fast. And getting up the only thing that I could think about is what just happened in terms of energy. The first thought that I had was how much potential energy I had at the top of the stairs. The next was how much transferred into kinetic energy from falling down the stairs. Then I thought about the mid way point where I had kinetic energy, potential energy and a little rotational energy.  I found this funny because physics changes the way you think, you can be sitting on your butt at the bottom of the stairs and still be thinking about how it relates to physics and then realize you have an EM exam on Friday!
  7. SJamison

    Friction Good or Bad

    By SJamison,

    A world without friction. That would be something wouldn't it? I cant think of something more hated and loved at the same time more than Friction. I started thinking about this at soccer practice the other day when it was raining out. I kicked a ball on the ground with spin on it but instead of curving it spun going in a straight line sliding a crossed the wet turf. With the coefficient of friction being lower on a wet surface this caused for less friction between the ground and ball causing it to not to curve the way i wanted it to but instead momentum carried it in a straight line. Going back to friction being loved and hated on the topic of a race car, I think this is where it is seen most. Without friction a car wouldn't be able to go forward and thus they need that friction if they want to go anywhere. BUT, then again they are also always fighting against friction trying to get their cars to go even fastest than they already do with things like bearings and probably the biggest air resistance. So thinking about Friction, we only like it was it works for us, not against us. 
  8. SJamison

    Golf

    By SJamison,

    The key to golf is not only patience but to have a consistent swing. If you can hit the ball the same way with the same force overtime you can be accurate with how far you hit the ball just by changing clubs. Each club has a different loft and an angle associated with it. Knowing the angle and the force exerted on the ball allows for you to be able to calculate the distance that the ball will travel using kinematics because you are able to find the horizontal and vertical forces suing the angle and these are needed to solve. And using a combination of force exerted on the ball and angle you are able to get an exact distance by changing these values. This will only work too if you know the changes in elevation and the idea that the ball is perfectly inelastic and that it has no rotational inertia which we know isn't true. 
  9. SJamison

    Hockey

    By SJamison,

    So this weekend my brother had a hockey game that I went to go watch. I traveled all the way to buffalo to watch his team get beat 5-2. Anyways, during his game he got absolutely destroyed at center ice. It sounds like it would really hurt but getting hit in the center of the ice isn't as bad as it sounds, getting hit against the boards it way worse which I know from experience (I have had my fair share of getting hit myself). But, this got me thinking of why it hurts more getting hit against the boards rather then at center ice. It looks as if it would hurt more getting hit at center ice but it actually doesn't thinking about force over a given period of time. Getting hit center ice means that the force that you get hit with is carried out over a longer period of time rather then against the boards meaning you will feel the force against the boards more because it is carried out over less time. Below are some examples of why it seems lik getting hit open ice would hurt more than at open ice. 
     
     
  10. SJamison

    Hockey shot

    By SJamison,

    Thinking about what we have been learning in physics, on the topic of energy, it makes it more clear to see some of the physics that goes into taking a shot in hockey. I mean they go so fast but getting there was a little hard for me until this unite that we are in now. Looking at elastic potential energy you can clearly see that in the picture below. It's crazy to see how that potential energy is turned into kinetic energy  in fractions of a second and the puck is sent flying at ridiculous speeds.
     
  11. SJamison
    So I recently came a crossed an article that said drinking warm liquids on hot days will actually cool you down faster than a cold drink. I found this really strange because I would have thought that a nice and cold refreshing drink would cool you down,however, like normal I was wrong. I thought that was really interesting so i decided to look into it. I found out that this is actually true. When drinking a hot liquid on a hot day it will cause you to sweat more than than usual, cooling you down. This is cool because with sweat being a natural cool down for the body it is cool how you can manipulate your body temperature so that you can do it more. Drinking a warm drink consistently allows you to produce about a 100 ml more sweat than if you were to drink a cold drink(A warm drink being 50 degrees Celsius and a cool drink being about 1.5 degrees Celsius) So if it a hot day and really want to cool down i suggest that you go grab some nice and hot tea even though a cold glass of water would sound better (which I will probably still drink on a hot day)
  12. SJamison

    Human strength

    By SJamison,

    A human body has the ability to release a huge amount of strength through its muscles. The reason that a person is unable to unlock all of this strength at any given time is so that muscles do not get strained or torn in the process. This is a cool safety feature of the body so that people do not over exert themselves and end up crashing. In order to produce large amounts of strength it takes a lot of energy and using muscles to their max for a long period of time can be very harmful to the body. However, in some cases when on an adrenaline rush people are able to tap into this strength in order to do things that seem to be humanly impossible. There have been incidents were people have lifted cars or moved heavy objects in order to save or do something. This shows just goes to shows how powerful the human body is.   
  13. SJamison
    When a person is jumping from a high distances to the ground or other hard surfaces it is important to maximizes the time that you are decelerating. This is vitally important because the thing that causes injury is the force that is applied to you over short periods of time. If you can spread the force out along a period of time the impulse over time wont be a as big thus your body will not have to absorb all of the energy at once allowing for a safe landing. This also allows for the body to be able to absorb greater forces. One way to increase the time to stop is by bending the knees. This is very important because if you don't you will feel the force all through your body
  14. SJamison

    Just a cool thought

    By SJamison,

    Today in class a cool thought was brought to my attention. The idea that an object that is an infinite distance away from all other objects will have no gravitational potential energy. Its a cool idea because if you think about any object on earth it has its own gravitational field due to the fact that all matter has mass. The earth is a great example of this because we can clearly see the moon and how it travels around the earth which is due to the gravitational pull by the earth on the moon. So thinking of the moon an infinite distance away from the earth than there would be no force acting on it saying that the only planets we are taking into consideration are those in this galaxy. It's weird to think this way with things at an unreachable distance becasue they are not possible and hard to wrap the mind around. 
  15. SJamison

    Knee surgery

    By SJamison,

    So in the past month I have recently had Knew surgery to remove a torn meniscus. This surgery was relatively quick only lasting about an hour. Knee surgery has come a long way from where it use to be. They use to have to open up the whole knee but now you only walk out with three little holes in your leg. All the thanks goes to physics and the ability to manipulate things using modern knowledge of optics and modern technology. During this surgery they were able to take out a torn piece of meniscus with a viewing tool, a small scalpel, and water to flush it all out. This makes the surgery relatively easy and allows you to walk a day or so after and be back playing sports within two weeks. I am very thankful for physics for it got me back to hockey before the season began. 
  16. SJamison

    Lasers

    By SJamison,

    Through photon camp in which I attended last year there was a lot of talk about lasers. This is because while using optics you can do a lot with lasers this is because you are easily able to manipulate them. The three things that all lasers have are an energy source, a medium and a resonator. The energy source or source pump is used to provide the laser with the energy that it needs to be powered. The medium is what really separates lasers because it determines the strength of the laser or the power that it has. And the optics are used to adjust and fine tune the beam. Lasers are cool because that have a variety of uses: cutting, welding, drilling, and marking. They are very good sources of light that are easy to manipulate and have endless uses.
  17. SJamison

    Monster truck flip

    By SJamison,

    In order for a monster truck to be able to do a front flip it needs for one of its points far from it's center of mass to come into contact with a fixed object. One way of doing this would be to get the truck into a wheelie or almost stand the truck up, then you need to hit a fixed object like a very steep jump. This will cause for the truck to begin a rotational motion and begin to do a front flip. This is because the impact of the tires on the fixed surface act as a torquing force which cause rotational motion. In the video below the truck hits a jump to get the car into a wheelie and then increases speed to hold the wheelie so that the trucks back tires come into contact with a dirt ramp which cases the truck to perform a front flip. 
     
  18. SJamison

    MRI machine

    By SJamison,

    So recently I had knee surgery, about four months ago on my right knee. Everything was going well and good until a few days ago. Come to find out I messed up my knee again but wait there's more, this time it was both of them. My right one definitely has another tear in the meniscus and the surgery is scheduled.  But, the left knee, however, we were unsure of so i had to get a MRI done. During this I was curious to see how it worked but come to my amazement so was the guy operating it. Despite this I decided to research how it worked. I found out that an MRI machine is just a strong magnetic field ranging from .5-1.5 Tesla. An MRI machine uses this magnetic field to arrange hydrogen atoms in the body along the axis of the machine. once this is done the nuclei produce their own magnetic field that can be detected by a scanner and then form an image.  I thought that this was really cool and the person to come up with an invention of this sort must have been absolutely brilliant. From this machine I hope that it gives me some good news so that I don't need three knee surgeries in a years time frame.  
  20. SJamison
    So last Friday our class of 22 had the pleasure of taking part in a Projectile Lab in which we would shoot our grade. In this lab we would be trying to hit a textbook after making various calculations. Another important aspect of this lab was the fact that if we hit this book the whole class would pass and if we missed the whole class would fail. As many of you know this lab didn't go so hot, crunched for time and lack of communication lead to a complete miss. Mr. Fullerton, being the wonderful man that he is, allowed us to re-due the calculation and write about it in the blog I'm currently writing to receive full credit after that humiliating miss. After doing the calculation again, I came to the conclusion that the book should have been placed at the center of about 2 meters. The thing that messed the class up the most was the fact that there was a lack of time and the push at the end caused for a mix up with numbers due to not being able to think clearly stressed about the time.
    After doing this lab and looking back on it, with some more communication it would have helped to make the lab go quicker so we aren't crunched for time also another idea would be to split into into small groups to get an answer which to then compare later instead of trying to work on it as a bigger group. I think that these things are key to this lab to allow for success. 
    Bellow are my calculations for the value in which the location of the book should have been placed.
     
     

  21. SJamison

    Skating

    By SJamison,

    So with the hockey season starting today I thought that i would do a blog about hockey. Thinking about skating in hockey and why you need to get your skates sharpened, this is to allow for there to be enough friction to propel you forward. This is just like running were you need friction between the ground and your feet to be able to drive forward by pushing back. The only difference is that in hockey you need the skates sharp to cut into the ice in order to drive yourself forward. This is showing Newtons law where if there is a force in one direction there must be one in the equal and opposite direction. Being able to gain traction is hockey is key to being able to be fast that's why you angle your blades on the ice instead of straight on as you can see in the video below. You can also see how the players you there sticks to go into the turn to help get around the turn more compact instead of having it out wide which would slow you down. 
     
  23. SJamison

    Spoiler

    By SJamison,

    So on the back of super cars you often find a spoiler. As a kid I always thought that a spoiler was just to make the car look cool but in fact it does serve many purposes depending on the positioning and type of spoiler used. One use of a spoiler is to push the air around behind the car as the car pushes through the air this reduces the drag force on the car. This application of the spoiler can improve gas mileage. Another reason why spoilers are seen on super cars is because when traveling a very high rates of speed it is often very difficult to control the car. By adding the right type of spoiler it can use the air that you are traveling through to push the back end of the car down, creating more downward pressure, this is know as counter lifting. This gives the car more grip that allows the car to have more power and control thus increasing performance. The car below is the mclaren p1, this is a car that makes use of a spoiler in order to keep it on the track and increase performance.  

  24. SJamison

    Stomping in the snow

    By SJamison,

    When you are walking in the snow have you ever noticed that when your foot lands in light, fluffy snow your footprint is actually bigger than it is and you can see the extra space with your foot still there? This happens because when you are bringing your foot down it traps a pocket of air between your foot and the ground. As a result of this once your foot hits the ground that air pocket is dispersed thus it causes for the snow around your foot to move even though you are not touching it. This can be pretty satisfying when you are walking home in the freezing cold with nothing to do.  
  25. SJamison
    @Cvankerkhove had a blog recently about the butterfly effect. The butterfly effect is basically the idea that every thing that happens has an effect on everything else so if one thing doesn't happen everything else could be different. This got me thinking about the idea of time travel and how things would change if you were to go back in time and interact with other people. With this idea in mind what would change? Would the time line that you went back to, continue on and basically start all over again by living out all of the changes that you made to it while the time line that you came from, continues to live out their time line? Or is their just one time line that is being altered? This idea of different time lines is kind of like alternate universes which is a cool concept and it makes me question the conciseness of us right now and how there could be multiple of you on different timelines.  

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