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  1. Crossbows are a very a cool weapon. They use tension and potential energy to shoot arrows. You first pull the string back, which requires a large amount of force, lock it in place with the spring system and then pull the trigger which drops the lock and sends the string and arrow launching forward at a high velocity. When the string is pulled back and locked in place, potential energy is built up. The more potential energy that is built up, the faster and stronger the arrow will launch once the trigger is pulled. Crossbows are fairly simple, yet very deadly.
  2. jdemers50

    An Physic C

    This year in physics C I have learned many things. Many of which have expanded my knowledge in physics and as a person. I have learned much about myself. I now know that I wont be able to understand everything the first time, that I need to work hard to achieve the things that I want, and that Mr. Fullerton is for the boys. While I haven't been the best student this year, I can confidently say that Mr.Fullerton has taught me many skills that will stay with me for the rest of my life. From teaching me about mechanics to E&M and to how to study, I have learned a lot. Physics C has showed me that I really like physics and that it is with out a doubt the most astonishing thing ever.
  3. jdemers50


    Ever wanted to know the physics of curling??? NO???? Well to bad im gonna tell you. Curling stones are made from thick granite stones, weighting about 20 kg, with a handle on top. The heavy mass of the stones makes it so it doesn't slow down early. The sweeping of the ice before the stone reaches that spot decreases the friction of the stone with the ice. The little bit of friction caused by the front of the stone melts the ice a tad and creates water which reduces the friction. By controlling the friction between the ice and stone you can perform curling.
  4. jdemers50

    An Harmonica

    The harmonica is by far my favorite instrument, I love the different types of music that can be played on it as well as the many different characters you find playing it. Recently I have been teaching myself how to play a harmonica and have been wondering the physics behind it. In each hole of the harmonica there lies a reed, all of which are different in size. When you breathe into the harp of the harmonica the reeds vibrate at different frequencies causing the different pitches you hear. Each reed is fastened to the reedplate with one screw, allowing the rest of the reed to vibrate freely. The harmonica can be very simple and some of it can be very complex. Once you become proficient at the harmonica you can learn how to bend notes and master the harmonica.
  5. Hey folks, breaking news, size doesn't matter. 100% of astrologists agree that a more massive planet doesn't necessarily have a larger gravitational force. Take Uranus for example, it very massive compared to us here on earth. In every way Uranus is larger than Earth, radius, mass, surface area, and volume. However because of earths smaller radius it has a larger gravitational force. The equation for gravitational force is F=G(M1M2/r2). The gravitational field on Uranus is 90% of that on earth. If you weigh 180 lbs on earth, ya gonna weigh 162 lbs on Uranus, pretty cool stuff.
  6. jdemers50

    I didgeridoo do

    The didgeridoo is an Australian instrument. It is made from eucalyptus tress hollowed out from termites. The didge is played by using a technique called circular breathing. Circular breathing is when you breathe into your nose and out of your mouth at the same time. It is much harder than expected but those able to master circular breathing can master the didge. The vibrations of the players lips and breath cause the air inside of the instrument to vibrate at different frequencies. When the frequency of the air matches the natural frequency of the air column it resonates. When the frequency's resonate it creates that big sound that you hear. The didges irregular shapes make its natural frequency very different from other wind instruments and make the didge quite unique.
  7. The Discus is a moment in which the thrower does some spin stuff and then launches the disk across a long distance. The discus has many factors in which effect the throw of it. The first being momentum. During the spinning part, momentum is built up and then the disk is released. In the air the disk cuts through the air because of its aerodynamic shape. Also the spin is a very important part of its flight. The faster its spins, the more stable it becomes. It is very important for it to remain stable because the more stable it is, the longer flight time and more distance you achieve. With all these factors in mind, explosive release, and perfect from will result in a great discus throw.
  8. jdemers50

    Week 2

    WOW! Very insight full!! Great work
  9. Integral to the operation of the mechanical watch is the balance wheel. Balance wheels are constructed of a weighted wheel and a spiraled torsion hairspring. The wheel is composed of a metal alloy with low thermal expansion, and the spring is made of either steel or silicon. Energy stored in the watch's mainspring is translated through the gear train to the escapement, a trident shaped piece with a dedicated escapement wheel which delivers impulses to the balance wheel. The balance wheel is what allows a watch to run accurately, as the balance wheel functions as a harmonic oscillator due to the constant mass of the wheel and elasticity of the spring. Balance wheel oscillations are determined by the time taken to complete a semi-rotation, called a vibration. Balance wheel oscillations are usually within the range of 28,800 vph (vibrations per hour, or 4 Hz), which ticks 8 times per second. The period of oscillation T of a balance wheel (one oscillation, or two ticks) is determined by the equation, T=2π*√(I/k) where I is the moment of inertia of the balance wheel, and k is the spring constant of the torsional hairspring.
  10. Writing physics blogs can be tough on the mind, soul, and body. It takes many minutes and many keystrokes to pump out a blog. It takes .045 Newtons per keystroke. Now add up all the keystrokes in this blog and you get a force of 12.87 Newtons. That's a lot of newtons!!!!! While this might not seem like a whole lot of force needed to type one of these blogs, imagine what its like when you slack off and have to write ten blogs in one day! Lots of force and lots of stupidity.
  11. The Guillotine is a device used to cut off peoples heads. It was used very much ion the french revolution and hopefully isn't used at all today. While to guillotine is often seen as a machine of death, the mechanics and physics behind it is often underappreciated. The blade of the guillotine is brought up to the top of the device and tied down to hold it in place. When the object that is in need of some chopping is put into the restraints the rope holding the blade is cut and the blade, which is quite thick and heavy is dropped and proceeds to cut the object. The blade is at a 45 degree angle and is brought down on a track with the force from the blade itself. The angle allows for a precise cut and because it is at the angle, requires a lesser force, which makes it more stable. The mass of blade determines how fast and hard the blade falls. The blade has the force of gravity, mg down and the force of tension T up. When the rope is cut/let go of, it drops with the force mg and chops whatever lies below. While the guillotine is quite brutal is was very efficient and innovative for its time period.
  12. Swings are found in children's playground and are very fun and enjoyable. They work just like a pendulum. A swing converts potential energy into kinetic energy as you swing. When you first get on the swing and take step back as far as you can to get the best swing you build up potential energy. When you pull your feet up and begin to swing your potential energy is converted into kinetic energy. When you reach the the maximum height form swinging your potential energy is built up and again is lost when you swing back down. By swinging higher you build more potential energy and swinging faster makes more kinetic energy. So remember that the next time you start swinging all's your doing is converting energy.
  13. Almost everyone can whistle and people often do it when they are bored or are whistling along to a song, but how exactly do we whistle? Well, you can only make whistling sounds at the resonance frequencies of your mouth, because at the resonance frequencies the pressure changes due to the moving air. You can change the resonance frequencies by changing the position of your tongue. By moving your tongue up and down, and blowing harder or softer, you can change the pitch and amplitude of your whistle. So if you wish to become very good at whistling you better get that tongue moving.
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