APlusPhysics Blogs

Showing blog entries posted in the last 365 days.

This stream auto-updates   

  1. Last week
  2. Nicholas Enterprises Starting Funds: $60,000 Vehicle Name: Mr. Rocket Vehicle Parts and Cost: MK16 Parachute X1, LV-909 Liquid Fuel Engine X1, FL-T800 Fuel Tank X1, TT-38K Radial Decoupler X3, RT-10 Hammer Fuel Booster X3, MK1 Command Pod X1, AV-T1 Winglet X3, TR-188 Stack Decoupler X2, Aerodynamic Nose Cone X3, FL-T400 X1, LV- T45 Engine X1. Total Cost- $12,182 Ending Funds- $47,818 Design Goals: Our rocket has been designed to successfully go into orbit around Kerbin and then return safely back to Kerbin. Launch Goal: Our goal for our launch is to go into orbit around Kerbin. Pilot Plan: The pilot should exit Kerbin’s atmosphere and then turn at the proper angle to cause the ship to go into orbit around Kerbin. Illustration:
  3. Earlier
  4. Glad to hear it went well. The center of mass concept is one that many times allows you to solve problems more simply than traditional 'plug and chug' formulas. You'll find it useful in a variety of units in the course!
  5. mad skimpy yo
  6. Not many people put a whole lot of thought into what their morning cereal is made of. Most people would just assume there's some grain and maybe a little sugar, or a lot of sugar if you're more of a Lucky Charms person than a Raisin Bran person. Nobody would suspect, though, that there would be metal in their Cheerios. Turns out, Cheerios are magnetic. Or are they? Fill a bowl with water and drop in a couple Cheerios. Take a magnet and hold it just above the Cheerios, the Cheerio will be attracted toward the direction of the magnet. Why is this? If the little cereal ring is magnetic, then there must be metal fragments in it causing the attraction. Now the cereal is all magnetic, and it does contain tiny fragment of iron. This is perfectly reasonable though, as iron is a key nutrient in a human diet. But that's not the whole story, If you were to try this with objects other than cereal, say a small piece of paper or plastic, it would still seem to be attracted to the magnet as it floated in the water. The "attraction" you see is actually all about water, which is diamagnetic, meaning it generates a magnetic field opposite to that of the magnetic field it is in the presence of. Thus, the water is slightly repelled by the magnet. This causes a slight divot in the water, that the object in the bowl actually falls into, making it appear to follow the magnet. In actuality, it isn't being affected directly by the magnetic field, but by the waters reaction to the magnetic field.
  7. Sounds like you'll have a head start on our "post-AP" project!
  8. Not quite sure I understand what "Mr. Fullerton is for the boys" means, but glad to hear you've gotten something out of the course. I, too, am glad you've stuck with it. Couple more weeks of pushing and the finish line is in sight!
  9. I was right with you up to the part where you said "it isn't that horrible of a movie." The missus made me sit through it once. The post-viewing fever lasted three days. I was right with you up to the part where you said "it isn't that horrible of a movie." The missus made me sit through it once. The post-viewing fever lasted three days.
  10. And of course there's that whole "Gallifrey and the Daleks are time-locked" complication. As corny and goofy as the show is, what always impresses me is the quality of the writing... and I'm really enjoying the fact that my 7-year-old is now all about watching Doctor Who with her dad whenever mom isn't home (Mommy would find it 'inappropriate.')
  11. So thrilled you've enjoyed the course. Recognizing it's the most technically challenging (as well as highest workload), and coupling that with an exceedingly frustrating instructor who is happy to sit back and let you struggle, you've done a mighty nice job in stepping up to the challenge. Only a couple weeks left... don't let up!
  12. You're on the home stretch of a mighty difficult course, not just in content but also in terms of level of independence. You've done well -- keep it up for just a few more weeks!
  13. Sure been nice having you in here!
  14. When a person swings a baseball bat and hit a ball with a wooden bat rather than a aluminum bat, it will generally not travel nearly as far. Why is this? This is a concept of momentum on the baseball field. The biggest reason for the ability for a person to hit a ball further with an aluminum bat is because when they do, they are able to swing the accelerate the bat to higher speeds than if they were to use a wooden bat. Momentum is directly proportional to velocity therefore the faster the swing of the bat the further the ball with travel in most cases.
  15. A common item such as a Frisbee has very complex physics concepts that explain why it behaves a certain way. The two main physical concepts behind the Frisbee are aerodynamic lift and gyroscopic inertia. The two main aerodynamic forces acting on a Frisbee are the drag and lift forces, these forces have a relation ship with one another and is used in order to determine the magnitude of either force. The rotation of a Frisbee is a necessary component in the mechanics of how a Frisbee flies. Without rotation, a Frisbee would just flutte rto the ground like a falling leaf and fail to produce the long distance flight that it does when thrown the right way. This is caused by the fact the aerodynamic forces are directly centered on the frisbee. In general, the lift on the front half of the disc is slightly larger than the lift on the back half which causes a torque on the Frisbee. When a Frisbee isn’t spinning, this small torque flips the front of the disc up, and any chance for a stable flight is lost.
  16. Swimming is a popular activity, both for recreation and competition. The physics of swimming involves an interaction of forces between the water and the swimmer. It is these forces which propel a swimmer through the water. When a person swims there are more forces acting upon them than you might think. First off a swimmer must push off the water in order to create thrusting force generally parrallel to the surface of the water, There is also the force of gravity on a person working in the y-direction however much of this force in cancelled out by the force of buoyancy. Lastly there is also some kinds of drag force That acts similar to a force of friction in the direction opposite of that the swimmer is moving in.
  17. Even the most fundamental things have physics concepts behind them, In physics, sound is a vibration that propagates as a typically audible mechanical wave of pressure, through a transmission medium such as air or water. This is also where physiology comes into play as well. The sounds we are all so familiar with are only our brains interpretation of sound waves leaving from somewhere else. Humans can hear sound waves with frequencies between about 20 Hz and 20 kHz. Sound above 20 kHz is ultrasound and below 20 Hz is infrasound. Other animals have different hearing ranges. How we interpret this sound will depend on the frequency of the sound waves that travel from something to a person.
  18. During archery in gym class, I'm usually one of the people who gets my hands on the nicer quality bows. But today I was sad to find myself with one of the weaker, green bows. I had never shot with one of these bows, so when I took my first shot the same way I normally would, I was surprised to find that it fell to the ground just before hitting the target. I realized that this was simple physics, and I could easily fix my shot. The green bows have much less tension in the string than the longer wooden bows, meaning that when released, they exert less force on the arrow. So my arrow was leaving the bow with a much slower horizontal velocity than normal. Obviously, the downward acceleration wouldn't change. So all I needed to do was to aim slightly higher than where I wanted to hit on the target, so that the arrow had more distance to fall, and didn't hit the ground before reaching its destination. After realizing I just needed to shoot higher, my shots were much improved.
  19. One of the endlessly fascinating things about physics is that it's in literally everything. Makeup is one of my primary hobbies, and I've noticed many aspects of physics in my daily routine. Whether you're using a makeup brush or a makeup sponge to get that flawless finish, you create a lot of friction on your face. In fact, the level of friction you apply will determine the quality of your application. Not enough, and you'll look a patchy mess. Too much, and you probably irritate your skin and defeat the purpose. A perfect balance of friction is what will lead you to a soft blend. Also, density plays a huge roll in makeup. When choosing between kinds of base makeup, from foundation to BB creams to tinted moisturizer, you have to know the kind of look you're going for. The denser the formula, the higher the coverage, and the thicker the finish. On a semi-related beauty note, static electricity is also a common battle in hair. This doesn't affect everyone, but being someone who has thick curly hair, I know too well the pain of having to carry dryer sheets to calm staticy hair. Lastly, every makeup lovers worst fear is gravity. The unfortunate acceleration due to gravity on all objects is never more real than when a compact or favorite pressed pigment slips from your hand and plummets to the ground. Seeing the powder shatter truly is a tragic moment, causing you to curse gravity. Everything is physics, and it can be fun to notice it in simple daily tasks.
  20. Citizens of the Rochester area experienced a weather crisis of dangerous proportion a couple weeks ago, to varying degrees. When I realized the power was down,I was excited for what I assumed would be a temporary break from school, and physics, but was disappointed. My father, being a type-A scientist type, found a way to bless me with the joy of physics even during our dark age adventure. My home had no electricity for days, and therefore no heat. We do, however, have a wood stove with a blower.The blower requires electricity, and my father keeps a deep cell battery for emergencies. So my dad would charge the battery on his car, then plug the stove blower into the battery inside the house. He used a voltmeter to periodically measure the voltage, to watch for when it needed to be recharged. He used this chart, not letting the battery drop past 30%, to be as safe as possible. And boy was I thankful for this battery, as it kept our home warm enough to live in and allowed us to charge out phones. Also, the monitoring of the battery kept my dad busy and out of my hair.
  21. The game Fifa has a displays many things parallel to physics in reality. In the game, motions of players and the ball as well as wind resistance. When you pass the ball through the air, the game mimics the parabolic path that the ball would take in a real live soccer game. Things such as the wind and the different players striking the ball are all accounted for. If the environment in the game is one of higher winds then different outcomes will occur when a ball travels through the air. Also in the movement of players momentum is heavily considered. If you were to play older Fifa game, the movement of players would seem unrealistic because they would be able to change momentum and accelerate themselves in impossible ways. In the newer games, when a player is moving full speed, it takes time for them to change their direction after having all of that momentum moving in some direction.
  22. Does everyone remember that day in science class when they told you the Earth was round, and you were like, "Yeah, no duh." And then a couple of years later they told you the Earth was also incredibly smooth, and you kinda just went with it. And then they said if you held an orange and a billiard ball in your hand, and then you could also hold the Earth, that it would feel more like the billiard ball than it would the orange? And that's when you got real confused. What about all the super tall mountains and super deep valleys and the trenches and the oceans? It made sense eventually though that these features were rather small compared to the whole mass of the planet. So now the Earth is one of the smoothest things you can think of. But there actually is one thing on Earth that is the most roundest, smoothest thing to exist on our planet: a ball of silicon. This sphere is officially the roundest thing humans have created; if it were Earth, the distance between its highest and lowest point would be 14 meters. The reason it was created is pretty cool too. The sphere is an attempt to create a substitute fir the current definition of the kilogram, as this measurement is currently dependent on a physical object called "The Big K" that is locked away in some basement in France. The problem is that there is no way to keep this object from being warped over time, and the definition of a kilogram therefore changed. The creators of the silicon sphere hope to use the amount of atoms in that sphere as a new constant that would replace the kilogram.
  23. In the last decade, the uprise of mobile devices with touchscreens has been prominent, and there are 2 main types of touchscreens. The first, and cheaper style, is known as resistive, which uses 2 separated films that when come in contact they allow current to flow. This is what is used to determine the location of the touch, as wherever the current is flowing is where the user is currently touching. The issue with this system is that it requires physical movement of the plates, meaning it can be triggered by anything pushing it together, also if it's layers are no longer even they can touch if nothing is pushing on them, causing unwanted actions. The solution to these issues is the more complicated design, known as capacitive touch. This uses a system of 4 capacitors on each corner, and when the touch occurs, based on how the capacitance changes, the computer system can determine the position of the touch. This is exceptionally useful for avoiding accidental touches, and for creating a much more durable touch surface. Also, it enables much more precision and ease of use to the user, as they don't have to physically move anything, and so there is less to go wrong. The disadvantage of this is that water and anything else conductive greatly reduces the accuracy and usability of such a touch screen, as it messes with the currents. Thanks to this kind of technology, it is much easier for us to use our mobile devices with ease and precision.
  24. First of all, unpopular opinion: The Bee Movie is awesome. It's funny, and cute, and you can't go wrong with Jerry Seinfeld. But as with any kids movie, the physics are way way off. What I found interesting though, was the movie's own mention of faulty physics, in the bees and their ability to fly. People always say that bees aren't supposed to be able to fly and scientists don't know how they can, but I called baloney and looked it up. The movie begins with a line "According to all known laws of aviation, there is no way a bee should be able to fly." Which is wrong. Turns out, scientists have figured it out, and the reason they hadn't before is pretty funny. They studied flight by comparing it to manmade aircrafts, instead of isolating animal behavior. Obviously insect flight won't always obey humans so called "laws of aviation". Bees have a freedom with their flight, and are able to change their wingspan in order to increase amplitude, without increasing the frequency of their wingbeats, which is higher than smaller bugs. This centuries old argument of the incapability of science can finally be put to rest. So don't worry Barry, we've finally got you figured out, keep flying buddy. http://www.livescience.com/528-scientists-finally-figure-bees-fly.html
  25. If a tree falls in the forest, and no one is around to hear it, does it make a sound? When a ball hits the ground or an axe hits a tree, we can hear a noise signaling this collision. Obviously, sound waves are produced, but where exactly do they come from? When two objects collide, one of two things can happen: an elastic or inelastic collision. In the case of elastic, no kinetic energy is lost. Inelastic, however, involves a loss of kinetic energy. Where does it go? Part of it goes to heat, but another part of it causes the sound waves to be produced because they need energy. When two objects collide, the molecules of the object vibrate a little, which in turn vibrates the air molecules, creating a longitudinal wave. So, if a tree falls, it does make a sound because the laws of physics don't stop just because there isn't a human to watch it.
  26. will beef fuel the writing of more than 30 blogs for Marcus and Jeremy?? Stay tuned to find out
  27. Conventional light bulbs use a filament, something to run current through that will heat up and produce light. These are very inefficient however, as more energy is put towards producing heat than light. This is why the idea for CFL light bulbs came about, which use a current running through gas to produce it's light. This method is more efficient, but still isn't perfect. This is where LED's come in, as they are small, very efficient, and require little power to produce a good amount of light. The reason why all lights haven't been replaced with LED lights is because of their cost, which while it's ever decreasing is still more than that of regular filament bulbs. This cost discrepancy is made more dramatic by the fact that LED's don't produce as much light per dollar spent, so for bright bulbs such as flood lights, it gets very expensive. In order to make a bright bulb, a large amount of LEDs are required, and this effect increases the brighter the bulb gets. This is exaggerated by the fact that if companies wanted to replace all of their bulbs at once, it would be expensive to install all of them, since many large buildings use a large amount of lights. I have an LED bulb in my room, and it is noticeably not as bright as a conventional bulb, but it will last a lot longer than any filament based bulb. Also, due to the fact that LED bulbs use circuitry, it isn't complicated to implement other things into the bulb. My bulb has a bluetooth speaker in it, which works very well considering it's inside of a light bulb. I think that in the future when LED technology becomes cheaper and better at producing light, all light bulbs will eventually become LED, unless they are specifically another type for one reason or another.
  1. Load more activity