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jwdiehl88

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Everything posted by jwdiehl88

  1. I have horrible eye sight, so that's why I need glasses to see better. And yet I never really understood how a mirror could make you see better. Until last year, when we learned in physics of optical glasses. Our eyes are concave, and the distance between our cornea to our retina is the focal length. So the light that hits our eyes allows us to see images. People who have twenty/twenty visions have eyes that aren't small or elongated and the focus is at the retina. This allows people to see images clearly. However people who have bad eye sight can either be far-sided or near-sided. The people who are far-sided, have their focus behind the retina because the eyes are short, therefore convex lenses can fix this. Convex lenses has a positive focal length which moves the image of a person far-sided forward. People who are near-sided, have their focus in front of the retina because the eye is elongated. Concave lenses can fix that because tit has negative focal length so it moves the image back to focus.
  2. I guess we can say that Lebron James wasn't a flopper through the use of physics! Draymond Green had an force big enough to knock down Lebron James, so Green should have been given the foul.
  3. Watching the summer Olympics last year was really intriguing because of the High Jump. I have always wonder how someone with just a pole could jump so high above a bar. Now I know there's physics behind it. First of all, before the person jumps above the bar, the person with pole has to generate speed to the high bar. This speed generate before the person jump increases the kinetic energy of the person. Then the person plants the pole down at an angle and jumps, the person is then able to be at the highest trajectory of their motion. Additionally, the kinetic energy of the person is then transferred into potential energy causing the person's height to increase. This allows the person to jump at a high height and be able to be at the highest point of its trajectory. The hang time of the person in the high is due to the pole's elasticity. The pole bends then whips the person to the bar, causing the person to have a longer time in the air. Then the person has to arc their backs to get over the high bar. Then they land on the soft pads to help their landing because it increases the time of the force impacting the body causing no harm to the body.
  4. It's hard to think about a how an explosion has momentum conserved because an explosions blows up everything in little pieces. However, those infinite amount of pieces all contribute to conserve the momentum of the explosion before it exploded. The law of conservation has a simple equation of mass times velocity initially equals the mass times velocity final. An explosion before it happens is equal to zero because it has no velocity at all. After the explosions, the pieces broken off in the explosion will go everywhere. The direction of the pieces matter because after the explosions, the direction of the pieces will have equal magnitude but just in the opposite direction. So when you had up all of the individual pieces of its direction, mass and velocity, the pieces will even each other out. Therefore the sum of all of the infinite pieces after the explosion will have a momentum equaling zero. Therefore the momentum of the explosions is conserved. It's crazy to think that the aftermath of an explosion has zero momentum.
  5. It's insane to think that baseball players throw over 100 mph by simply using torque of their body.
  6. That's really cool because this physics could be applied to any other objects at equilibrium.
  7. That's really cool, it reminds of all the time I see people who do park core and when they jump from a high height they roll after the land to absorb the force on them.
  8. Yeah exactly, as a fellow tennis player, its cool to think about physics behind it. Tennis is a game full of conservation of energy.
  9. Wow i never knew that the sizes and thickness of a bat affected so much of a baseball players power and torque.
  10. Roller Coasters, how do they move so fast without any motor pushing them? Energy! More specifically kinetic and potential energy. In the beginning of a roller coaster ride, there is an ascension to the top of hill. The purpose of this is that as the roller coaster gets higher and higher up, it gains potential energy. You could calculate this by doing mass times gravity times height. After the the roller coaster reaches to the top and starts fall down, the potential energy is then transferred in kinetic energy, which moves the roller coaster. Kinetic energy can be calculated by doing one-half times mass times velocity squared. Energy can never be destroyed or created so the the roller coaster has a constant energy total. Therefore kinetic energy can be also transferred to potential energy. This is why roller coasters can move without any motor pushing it.
  11. Sledding, a fun activity to do over the winter, applies to Newtons laws of motion. Newton's First Law of Motion, the Law of Inertia, states that an object will not change unless it is acted on by an outside force. This means that an object at rest will stay at rest until a force causes it to move. Additionally, an object in motion will stay in motion until a force stops it. When you are on top of a hill, there is no force pushing on you therefore you don't move. When you go down the hill, the force of gravity is on you therefore you have some velocity. When get to the bottom, the force of friction slows you down until you stop. Additionally, the acceleration of the sled is affected by the frictional force of the snow to the sled.
  12. What is wi-fi? I used it all the time, but never really knew what it was. Wi-fi uses radio waves and sends out these waves to different devices to give them the power of the internet. They send out around 2.2GHz - 2.4 GHz, These waves have similar frequencies as mircowaves. These waves travel through the air, undetectable by the blind eye and they send out "information" to other devices. The reason why people lose connection to their wi-fi after traveling some distance is that waves can only travel a certain distance. Also the reason why wi-fi can be slow is because they can be blocked by interference by other waves crossing them. Additionally, there are certain amount of waves available, so the more devices connected on the wi-fi, the slow the connection will be.
  13. jwdiehl88

    Blogmas Day 7

    That's pretty cool how you combined physics through newton and calculus through his law of cooling .
  14. Ten months from now, I have to do my own wash, so my parents are making me practice now. Anyways, while I was doing my wash, I realized there is physics behind the washing machine rotating the the clothes around. I realized that someone could calculate the centripetal force of the machine. A person would have to mass the washing machine, then a person would have to measure the radius of the machine. Then to find the velocity of you would use kinematics. First you know the amount of time of the washer machine because you can set it up. Then a person could calculate the rotational distance. Measure how long it takes for one revolution. Then with the rotational distance, it could be translate it to translation distance, with the radius known. Then the person could find the velocity of the machine. With that, the centripetal force could be found with mass times velocity^2 divided by the radius.
  15. Cello, the best string instrument, creates beautiful music. But how does a cello create sound? Well, sound is produced by the vibrations of the string, and these sounds resonate inside the cello. Cello strings are fifths (five notes apart) and each string creates their own frequency when you place your finger down on different parts of the string. As you place your finger down the fingerboard to the bridge of the cello, it creates a higher frequency. As you place your fingers up the fingerboard, it creates a lower frequency. Each string has different frequencies because of the thickness/wavelength of the string. The more thick/smaller wavelength the string is, the lower frequency the cello creates. Additionally, cello's have harmonics on each of the four strings. Each at a difference frequency and when you play the harmonic, it produces a loud clear sound. When you play a harmonic, this creates a shorter wavelength which in turn produces a higher frequency sound.
  16. jwdiehl88

    Lava Lamps

    That's really cool. I didn't know that inside the lava lamps were wax and water.
  17. jwdiehl88

    Knee surgery

    Yeah it's remarkable how much time and effort is saved through new medical techniques. It's even cooler that physics attribute to the new technologies.
  18. That is crazing! I can't imagine the force, the amount of work and the amount a power people have have to do this competition.
  19. Apparently, I have a mole that has a small chance to become cancerous, so I have to undergo laser surgery to get rid of the mole. That lead to me to think, how is it possible that a laser could remove skin off a person's body, without hurting the surrounding skin. So I learned that LASER is an acronym the represents Light Amplification by the Stimulated Emission of Radiation. So basically, lasers emit monochromatic (single color/wavelength) light that are designed to send ultra-pulses of light energy which is used to remove moles from the skin. The heat/energy of the laser is absorbed by the pigment of the mole, it heats the mole up, and then he mole burns away. Lasers are produced to have specific wavelengths of light that are being absorbed by certain pigment of the mole and not affect the surround skin cells. When the laser energy is applied for the right length of time, at the right level of energy, and in the proper wavelength, the mole on the skin is selectively targeted. This is why laser surgery is harmless to the surround skin of the mole.
  20. I used to practice martial arts and one day in our dojo, my sensei decided that we should have fun by breaking boards. Although breaking a board seems impossible for a person who doesn't do martial arts, it is quite simple if we look at the physics of breaking a board. For example, a person needs to generate a certain velocity to impact the board at a certain position. A person should make the impact/position of where your hands end, up past the board. Otherwise your hand will have a tendency to slow down when it reaches the actual position of the board. Additionally, a person should position their strike on the board where the board it weakest. For example if you punch the center of the board, it is harder to break it because that's where it is the strongest. On the other hand, if you punch a board at the near an end of the board, it will break more easily. It can still be very hard to break some boards because of how the thickness of the board. As the board increases in thickness, you velocity of the strike has to be fast and more precise on the board.
  21. Oh yeah i remember this last year. Where the two sound waves meet, is where there is destructive interference, so if a person stood there, the noise of the two crowds wouldn't be very loud.
  22. Assassins Creed has so much physics behind it. Especially when you are able to free roam the game and are able to do park core by climbing mountains, jumping from tree branches, jumping off of ledges, and so much more. It's cool how realistic it is.
  23. Shooting a puck, wrist or slap shot, requires a player, using their stick to apply a force greater than the frictional forces(very little, due to ice being relatively smooth) resisting the puck's movement. Players have the ability to generate lift because all stick blades have a certain "tilt" angle.(the face of the blade is turned slightly upwards). During the shot, the puck slides along the face of the blade and it is the tilt which allows it to be lifted off the ice surface. Players who generate high speed velocity of their slap shot, has a large force and time of impact of the blade and hockey puck. Players wind up for a slap shot, to generate a large force and then hit the hockey puck in a certain time. Force * time = impulse = change of mass * velocity. Therefore a large impulse equals a pretty large velocity. Players who attempt wrist shots, have a less wind up because they want more accuracy then power. The less force the player has on the hockey puck from the blade of the stick, means less impulse. Therefore a lower velocity of the hockey puck relative to the hockey puck hit by a slap shot.
  24. That's cool how the tennis ball travelled next to the car, but eventually it would fall due to air resistance.
  25. How is it possible when you bunny hop, there is no friction and you increase your speed?
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