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Everything posted by bazinga818

  1. Team Name: Axburns Inc. Available Funds: $30,000 Vehicle Name: Axburn I Vehicle Parts List and Cost: Rockomax BACC Solid Fuel Booster ($800), Mk2 Cockpit ($1600), Tail Fins ($1000), Decoupler ($600), Parachute ($400) Total Cost: $4400 Design Goals: We wanted to design a vehicle that would launch successfully and stay upright in the air. We used the fins to keep the ship on course and the nose to facilitate aerodynamic-ness. Launch Goal: We wanted to get to the 50,000m milestone, but we were happy with getting over 10,000m. We reached a maximum height of a little over 31,000m. Pilot Plan: Operating the winglets, control pitch Illustrations:
  2. Basically what I've gathered from this is that Ryan Gosling is a lumberjack
  3. Basically what I've gathered from this is that Ryan Gosling is a lumberjack
  4. Honestly, this whole E & M section of Physics C has not been going so great for me. We're supposed to have our last unit test on electromagnetism tomorrow, but I took it today because I won't be here tomorrow. We finish it the Monday after break, and it's safe to say I left about 75% of that test blank because I didn't know the answers. I think I struggle with concepts more than anything. I just can't visualize the problem like I could in mechanics, so none of the processes we go through to get answers seem logical to me. Anyway, I need to work on memorizing formulas too. I know induced current is big and necessary, but unfortunately today I forgot that equation during the test. I also need to study capacitors and inductors and how they act in circuits, as well as how to use all those equations with e in them in the RL/LC circuits . I think a huge contributor to my misunderstanding is how I watch the videos. I watch them and take notes, but don't always comprehend what the point(s) of the video was/were, and then I go a couple days without looking at my notes on them and I forget almost everything. As you can see, I have my work cut out for me over break. I know this isn't a typical blog post, but I also know that I am running out of ideas, and this helped me work out my issues which is good. Until next time, bazinga818
  5. Since I just rode up one, and because I can't think of anything else to write about at the moment, I guess Ill do the generic elevator blog post. So, elevators. One of the first things we did in Physics B when learning about free body diagrams, was practice elevator problems. First, in all out FBD's, we would have to draw our weight=mg pointing down because the force of gravity acts downward. Then the normal force, or the force of the elevator pushing up on your feet, would point upward. If the elevator was not accelerating, weight=normal force. However, if it accelerated upward, the floor pushes on your feet with an even greater force, so if you were standing on a scale you would weight more than your actual weight. In accelerating downward on a scale, the scale would show you weighing less than your normal weight. A shorter one, but you get the idea. Thanks for reading. Until next time, bazinga818
  6. See what I did with the title there? I'm so clever. So, echos. An echo happens when you say something or make a noise and the sound waves from your mouth bounce off a hard surface and rebound back to you, which is why you hear what you said again and again and again. This is why echoes are common in caves, because you're surrounded by hard surfaces. We know that when a wave reaches the end of its medium, it undergoes a certain process depending on how it's medium ends. Transmission/refraction, diffraction, and the one that causes echoes: reflection. Awhile ago I stumbled upon something really cool involving echolocation, which is the ability to make sounds and determine where and sometimes what certain objects are in a room. I watched an especially awe-inspiring video, showing blind people that had learned to use echolocation; an object was placed on a big table in front of them, and by making clicking noises with their mouths, they were able to determine where on the table it was placed and even what shape it was. Some even guessed the objects. I wish I could link the video, but since I can't I do hope you'll try to look it up and maybe someone can find it. I thought that was pretty amazing, to be able to see in a completely new way. Yet another awesome application of physics. Until next time, bazinga818
  7. And on we go, talking about more physics in Newton's Cradle. We already talked about conservation of energy, so now let's talk about conservation of momentum. Momentum is a vector quantity, meaning the direction it's in matters. When the first ball is dropped into the second ball, the second ball must keep moving in the same direction, and the first ball doesn't just bounce off the 2nd in the opposite direction; this would be a change in momentum, which cannot happen without the application of an outside force. So in order to conserve momentum, the energy must move in the same direction through all five spheres. Of course, Newton's Cradle isn't a completely closed system so as to warrant conservation of momentum, as the force of gravity and friction will always act as outside forces. But for the sake of this explanation, we'll assume we live in a perfect world without gravity or friction and everything is a closed system. Then, the collisions in Newtons Cradle would be perfectly elastic, where kinetic energy is conserved as well as momentum. A bit drab, but hopefully you stayed awake till the end. I'll try to make the next one more engaging, but it's hard to find motivation in a dark hotel room while you're leaning over your phone listening to your parents snore and typing about physics instead of partyin it up in Pittsburgh.
  8. We've all seen it - that contraption with 5 metal balls hanging side by side on strings? You lift one to the side as if it were a pendulum, let it go, and it swings into the others - causing the ball on the very opposite side to go up. This is called Newton's Cradle, named after the big guy himself. There are a number of physics laws at work here. First, the law of conservation of energy: as potential energy is maximized and kinetic energy is zero when the end balls swing to their highest point, thus kinetic energy is maximized and potential energy is zero at the bottom of its path. However, while kinetic energy is maximized, the ball is suddenly stopped short by the next ball at rest at the bottom of this path. The end sphere stops moving and it's kinetic energy becomes zero, but since the law of conservation of energy states that energy cannot be created or destroyed, that energy has to go somewhere. So it goes into the second sphere, on into the third, fourth, and finally transferred into the fifth where this ball uses the transferred kinetic energy to move away from the pack in a pendulum-like arc upward, mirroring the first sphere's movements. Voila! Conservation of energy at its finest, explaining cool doo-hickies like Newtons Cradle. There's more physics to this contraption, but I think I'll expand on it more in my next blog post. Thanks for reading! Until next time, bazinga818
  9. You read that right. Aw yeah you read that right. We're talking about DOING THE WORM.
  10. Recently I sat at the table eating dinner, when I noticed a flutter in my peripheral vision, drawing my attention. I turned my head to see my cat batting at a cat toy someone had hung from the table...one of those sticks with the string attached and a feather or fluffy thing at the end, ya know? You wave it around like a wand and your cat pounces after it? Anyway, someone in my family had set it up so just the string and attached feather hung down over the table, just within my cat's reach. She batted at it playfully. It was then that I realized...hey! More real-life physics applications! This cat toy was an example of a pendulum! When we learned about pendulums, we learned that they have a period of oscillation, or time it takes for them to complete one cycle, to swing forward and back to its original position. We learned that pendulum's periods of oscillation DO NOT depend on the mass of the object at the end of the pendulum (as with springs), but rather only depend on the length of the pendulum and the acceleration due to gravity. For a perfect pendulum (weightless string, perfect conditions, etc), the equation for the period is T = 2(pi)radical(L/g), or 2 pi times the square root of length of the pendulum over acceleration due to gravity. Unfortunately, my cat's toy wasn't a perfect pendulum, and the feather at the end inhibited the period time due to the air resistance it created...but oh well, she didn't seem to mind. Thanks for reading! Until next time, bazinga818
  11. Recently (on a much cooler day), I discovered something while driving to volleyball practice at night. It was chilly so I had the heat on in my car, but just on low. Upon turning on the highway, I suddenly noticed that the heat seemed to have been turned up! That wasn't right, how could it do that on its own?! I double checked it, but the switch hadn't moved; the heat was still on the lowest setting. So why did it feel like hot air was blowing twice as fast into my face? Well, when I thought about it, the answer was simple: inertia. As the car accelerates forward (as it does when entering a highway), the objects - including hot air - inside the car want to stay put. This is the same reason why you feel thrust forward when you slam on the breaks, or slammed against the wall when you make a sharp turn. Your body wants to keep moving in a straight line due to inertia (as Newton says, "an object in motion tends to stay in motion"). So, what does this have to do with the hot air in my car? Well, it too has inertia and wants to stay at rest unless acted upon by an outside force, so when I accelerated onto the highway, the hot air stayed in place. Since the car itself was accelerating forward while the air stayed put, it made it feel like the hot air setting had been turned up as it blasted in my face. In reality, it was me (and the car) accelerating into the hot air. Anyway, I thought this was pretty cool. Hopefully you thought so too! Thanks for reading. Until next time, bazinga818
  12. It was first Aristotle who discovered what is now known as the Mpemba effect: that hot water actually freezes faster than cold water. Scientists have struggled to explain this for years, until recently. We all know that "water" is made up of two hydrogen atoms and an oxygen atom, more accurately known as H20. Cold water is made up of short hydrogen bonds and long O-H covalent bonds, while the opposite is true for warm water. It is these hydrogen bonds that act weirdly and have drawn the attention of scientists. Some strange, unexplainable facts about these hydrogen bonds: 1. Although they're generally weaker than covalent bonds, they are stronger than the "van der Waals" force that is the sum of all attractive forces between molecules. 2. Chemists have suspected for awhile now that it is these hydrogen bonds that give water some of its weirder properties, such as allowing its boiling point to be so much higher than other liquids of similar molecular make-up. The hydrogen bonds hold it together very well. Anyway, though the hydrogen bonds bring water molecules into close proximity, the molecules are naturally repulsed by each other and as a result stretch away from each other and store energy, increasing heat. When the molecules shrink again and lose their energy, they begin to cool quickly as a result. Voila! The Mpemba effect. That was a simplified explanation from someone who hasn't touched Chemistry in two years, so I apologize if any of it is incorrect. Hope it gave you some insight, at least! Thanks for reading. Until next time, bazinga818
  13. Warning: this blog post may get a little gross if you don't like mucus-related physics talk. Reader discretion advised. So, ever wonder just how fast you sneeze? Or rather, how fast the snot comes out of your nose when you sneeze? Well, so did Adam and Jamie on Mythbusters. They investigated a myth that when sneezing, the mucus can eject from your nose at speeds of up to 100mph. That myth was busted though, and they instead found snot-rocket speeds to be only about 35-40mph. Still - that's the speed a car goes on most streets, and it's pretty fast. Imagine how far you could shoot snot rockets...the snot would act as a projectile that we could use our projectile equations on in order to find the initial velocity. Jamie and Adam did just that - see how far theirs went: Gross! Well, that's about as much as I can take on the subject...thanks for reading! Hope you found it interesting. Until next time, bazinga818
  14. You could always go for a bowling ball instead. But maybe that's up too high on the list of "ways to ruin someone's day"
  15. The Physics-C midterm approaches. While frantically searching the depths of my mind (and the internet) for an idea for my last blog post, I looked up to realize the time and scolded myself for not finishing these blog posts earlier. Why do I always wait until last minute? This is time I could have used to study. So in a feeble attempt to finish in time to cram in some legit studying (because I don't think blog-post writing counts as studying) for both Econ and Physics tomorrow, I decided to write about the midterm and what I'm worried about/need to study, etc. Let me start off by saying I am so so happy there is no E&M on this midterm. I'm definitely dreading the months to come in learning more about that subject, and having to take an entire exam on it in May. Yikes. But luckily, our midterm is all Mechanics. Still, I definitely have a lot to be worried about. Most of what I'm nervous for is stuff we've learned this year, especially the long derivation-heavy physics-y type problems we'll have to do or know for the part two's. Just part two's in general, I know I'll have trouble with. I think the best way to remedy this would be not only to look over the practice FRQ's we've done, but also to look over the problems we've done in our notes and maybe try a few on my own. I've noticed I also have trouble with vectors and dealing with things in more than one dimension or direction. I sometimes ignore things I'm not supposed to ignore or combine things I'm not supposed to combine or something along those lines. I'll definitely have to look over those 2D momentum problems, for one thing. Also, dealing with real pulleys will inevitably throw me off. Moment of inertia problems, too. As far as the multiple choice goes - I feel a little better about that, but still not super confident. I often make stupid mistakes, so I'll need to try to minimize those. And timing - I definitely need to watch out for that. Okay, it's getting late so I'm going to wrap this up and squeeze in some last-minute studying before I crash for the night. At least I don't have to worry about getting my blog posts done anymore! Good luck to all the physics students (regents and AP) taking their midterms this week! We're halfway there. (insert Bon Jovi jam session here). Wow, I must be really overtired. Thanks for listening to my rant! Until next time, bazinga818
  16. That's okay, I already did it for you! No n this time
  17. Cow tipping - is it really possible? We've all heard about that awesome prank the teenagers of our parents' and grandparents' generations used to pull...but can it really be done? First off, I'd like to assert that in no way do I condone cow-tipping or the bullying of any other farm animals. Because hey, cows are people too. Anyway, onto the physics. First off, cows don't even sleep standing up, contrary to popular belief. So, assuming they stay in place and don't run away when you try to sneak up on them (an unlikely wager to begin with, because who wouldn't run away when someone was trying to push them over?), once you started pushing, they'd do everything in their power not to be tipped over. Cows weigh a lot - we know this. And according to Newton's 2nd Law, F=ma, you'll want to apply a big force as fast as possible to have any chance at knocking the cow over before it can react. I actually found a diagram and calculations about the physics of cow-tipping someone had already compiled: Adapted from Popular Mechanics, using the work of Margo Lillie and Tracy Boecher. So you see, it's pretty impossible for one person to tip a cow, even if cows did sleep standing up - they're just too heavy. You'd need at least two people for that, and 5 or 6 if they cow were awake and able to take a wider stance and brace itself better against your cruel intentions. And it's a good thing too - I mean come on people, the poor cows. Thanks for reading, hope you don't try to test this one out for yourself! Until next time, bazinga818
  18. I recently stumbled upon a question that definitely made me think twice. And then twice more. If you carry firewood to the top of a hill, and then burn it there, what happens to the firewood's gravitational potential energy? Does it disappear? Crazy, I know. The equation for gravitational potential energy is mgh, or the mass times the acceleration due to gravity times the height. If you burn the log up into ashes with substantially less mass, what happens to the rest of the gravitational potential energy the logs had when you carried them up the hill? Honestly, the hill part doesn't even matter. Whether you burn the wood up on the hill or in the valley below, it's still gone either way. The hill just makes the height component of gravitational energy easier to visualize. But where does this seemingly lost energy go? It can't just disappear right? All we've ever been taught in physics is that energy is conserved! Right?! It's true, it can't disappear - it just becomes harder to find. When the wood is burned, a lot of the energy escapes in the gases released from the fire. The gases are released over a long period of time as the fire burns, so it's hard to visualize them weighing as much as the wood you're burning - but it's true, just about. If you compressed all the gas that is released from the moment you start burning the wood to the moment the last ember crumbles, it would weigh just about as much as the wood did originally. Thus, the same potential energy. So the energy didn't go anywhere, it just escaped in a different form. There are some other factors in play here I still don't quite understand, but this is the gist. Maybe I'll look into those other factors and expand on them in a future blog post. This is where I learned about this topic, and you can too: howeverythingworks.org. This guy really knows his stuff, and probably explains it better than I can. Make that definitely explains it better, since I still don't fully understand it. Hope I made a little bit of sense anyway. Thanks for reading! Until next time, bazinga818
  19. When I saw this post on the main page the "n" in moon was cut off so I thought it was going to be a blog post about cows and I got really excited. But I guess this is pretty cool too.
  20. Did you know that, when you wear high heels, you can literally dent the floor? (A wooden floor, of course.) So not only do these things torture your feet, but they also do damage the floor you walk on? Still worth it? Let's say you're a girl, drag queen, or just a regular guy who enjoys wearing high heels from time to time, and you weigh about 130 pounds. Let's also assume your shoes - regular flats, that is - have a bottom surface area of about 10 square inches. With heels, the bottom surface area that comes in contact with the floor could be half that, or even less. While you are wearing flats, your shoes push against a large area of the floor and thus the pressure (force per area) is relatively small - about 13 pounds per square inch. However, in heels, you still exert the same force downward due to your weight - just over a smaller surface area. So the pressure would be around 30 pounds per square inch or more. And what if your heels narrow into a single spike, that takes up only .1 square inches? And then, if you put all your weight on your heels (it's fun to see how long you can balance sometimes, am I right?)? That's 650 pounds per square inch! And if you try balancing on just one heel?! 1300! So yeah, you get the idea. Wearing heels drastically increases the pressure you put on the floor, which makes it more likely you'll put dents in it or damage it in some way. So if you're looking for an reason to stop wearing them but don't want to admit to the stereotypical cop-out "they make my feet hurt"...try this more creative excuse. But I'm pretty vertically-challenged as it is, so I think I'll take my chances. Thanks for reading! Until next time, bazinga818
  21. We've all heard the myth. Drop a penny from the top of the Empire State Building, it will gain enough velocity to do considerable damage to someone standing on the sidewalk - plunge a hole through their hand, or, in more gruesome versions, their head. Though at first this thought seems plausible (considering the height of the Empire State Building and the acceleration due to gravity), it's important to realize that - due to other important factors - this myth is busted. When we first release the penny from the top of this skyscraper, it begins to accelerate downward at 9.8 m/s^2, the acceleration due to gravity. If the only force on this penny were the force of gravity downward, it would continue to accelerate at a constant 9.8m/s^2 until the moment it hit the sidewalk. Since we know the height of the Empire State Building is about 381m, and we also know the acceleration is 9.8 m/s^2 and initial velocity (Vo) is zero, we can calculate the final velocity (Vf) using our kinematics equation: Vf^2 = Vo^2 + 2ax. Plugging in those numbers, we get that the penny would be traveling about 86.4 m/s just before it struck the sidewalk or person on the sidewalk. For those of you who find it hard to comprehend just how fast this is (because here in the US we say "screw the metric system!" ), this translates to roughly 193 mph. Yeah, that's pretty fast. But wait! There's more! We forgot to account for one crucial detail, the very detail that makes this myth a bust: drag. As the penny falls, it experiences another force - the force of drag, or air resistance, acting opposite the force of gravity. For its weight, the penny drags an awful lot of air behind it. As a result, it reaches terminal velocity at only about 25 mph. So, there you have it. Because of the force of drag/air resistance, tourists below the Empire State Building have nothing to fear from falling pennies. Hope you enjoyed this blog post! Until next time, bazinga818
  22. I could point out that you can't rhyme physics with physics, but other than that, impressive. I enjoyed your use of "heart attacka".
  23. Static electricity is a stationary electric charge that is built up on a material. We might experience static electricity when touching a doorknob or rubbing our feet on the carpet and shocking a friend - sometimes we can even see a spark. This static electricity is formed when we accumulate extra electrons and they are discharged onto another object. So we know that electrons are tiny negatively charged particles, and protons are tiny (though not nearly as tiny as electrons) positively charged particles. Electrons move around in the outer shell of an atom, while protons and neutrons (neutral charge) reside in the center of the atom. Sometimes the outer layer (the negatively-charged electrons) of atoms are rubbed off, producing atoms that have a slight positive charge. The object that did the rubbing will accumulate a slight negative charge as it gets extra electrons. During dry weather especially, these excess charges don't dissipate very easily, and you get static electricity. So here's a good static electricity experiment: rub a balloon on your hair. Some of the electrons from your hair jump to the balloon, giving it a slight negative charge. Now if you put the balloon against a wall, it will stick since the negative charges in the balloon will attract the electrons in the atoms of the wall. Hope you enjoyed this short blog post and learned something about static electricity! Until next time, bazing818
  24. It is often believed that, when turning in a car, you lean the opposite way of the turn. Turn right, you feel a force left. This is a common misconception. In actuality, as the car turns right, our bodies' inertia (directly proportional to mass) keeps us wanting to travel in a straight line, which is why we feel thrust leftward. This is also why, when we slam on the breaks, our bodies jerk forward - they want to keep going straight. The above explanation makes sense, but I've always wondered why we didn't feel a force inward in circular motion if the centripetal force points to the center of the circle. So I did some research, and learned some more about it. An inward net force is required to make a turn in a circle: the centripetal force. In the absence of any net force, an object in motion continues in motion in a straight line at constant speed (Newton's first law: an object in motion stays in motion unless acted upon by an outside force). In a right-turning car, the passenger slides left. In a sense, the car is beginning to slide out from under the passenger. Once they strike the left door of the car (or their seatbelt holds them in place), the passenger can now turn with the car and experience some circular motion. There is never any outward force exerted upon them. The passenger is either moving straight ahead in the absence of a force or moving along a circular path in the presence of an inward-directed force - the centripetal force. The car itself is what provides the inward centripetal force, even if we as the passengers don't feel the force directly. So hopefully that clears up any questions you had about feeling centripetal force. I'd been confused about this concept for over a year now, so researching it definitely helped me understand it better! Until next time, bazinga818
  25. Parkour, sometimes referred to as "free-running", has always fascinated me. How do they do it? I for one can't even do the simplest of parkour stunts, but I looked into the physics of it a bit, and thought I'd share what I found. Of course, these stunts seem scary to us because, frankly, they hurt when we try to do them. Or when I try to do them, anyway. In order to make it hurt less and avoid broken bones - to lessen the impact upon landing after a fall, or to decrease the force upon a set of fingers while grabbing onto a wall - it is essential to reduce the acceleration during each collision as much as possible. This relates to Newton's 2nd Law, of course, as F=ma. Increase the acceleration, decrease the force, as there is an inverse relationship between the two. To do this, one would increase the time of impact by smoothly bending, flexing, or rolling during impact. Let's apply some of the physics to an example. During impact with the ground, there are essentially two forces acting on your body -- the downward force of gravity (mg) and the upward force of the ground. Applying Newton's second law we get: Fnet = Fground - mg = ma So let's say that I jump from a height of 3.0 meters onto the ground. How much force is the ground going to exert on me during impact? First, let's apply conservation of energy to determine my speed just before contact. The gravitational potential energy (mgh) due to my initial height relative to the ground is going to be converted into kinetic energy (½ mv2) just before landing. So Mgh = ½ mv2 and v = [2(9.8m/s2)(3.0m)]1/2 = 7.7m/s Now I have to be brought to a stop. Fground = m(g + a) = m(9.8 m/s2 + a) We can see that the force of impact depends on the acceleration. But acceleration = change in velocity/change in time and therefore depends on the time of impact. Therefore, if I land on heels and stay stiff, I could be hurt or break a bone. However, if I land on the ball of my foot and bend my knees or duck into a roll upon impact, the time of impact can be increased dramatically. By decreasing my velocity over this extended period of time, the force is substantially reduced. So there you have it, the physics of parkour. Now I can go apply this and become a parkour beast. (Or break my neck. Let's hope for the former.) Please enjoy the awesome parkour video I found below. Until next time, bazinga818
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