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  1. Blog Doctor Why

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    Recently I've been thinking: Do i really want to take C in high school? So far i feel completely overwhelmed but have been waiting for that "ah-HA!" moment that seems to be drifting away. I think of the students that are taking ap econ, calc BC and physics C, and they seem to be doing just fine, so why can't i seem to handle ap econ, calc AB and physics C? I would feel quite frankly, like a lame quitter if i dropped out, and even the term "dropping out" has, "you fail" written all over it to me. But at the same time I'm afraid that i've overloaded myself and all my grades will suffer from it especially when the material gets more difficult. And the reason i'm doubting my choice to take C is that out of all my AP's, im most confused in this one. Also I researched and most the colleges i'm applying to wont take 2 ap physics credits. Also the curriculum of the degree i want (5 year professional degree in architecture) in the schools i have in mind wont even let me take physics 101 until my sophomore year (Syracuse), or don't require me to take it at all (Cornell). Which i thought was strange but all electives say "free in department elective" or "free out of department elective." But if i do have to take it again in college, are the benefits of taking it now worth all the stress this year? Additionally, if i end up using it as an actual architect which i assume i will, I would rather take it closer to when i'll actually use it so i remember the material. In short, I really don't want to be taking this course *at this time.* Don't get me wrong, i'm interested in the concepts and material, I just don't know if i can handle it right now with my other aps, the truck load of college stuff we have to take care of, and general hygiene.

    sincerely

    Stressed Out / Worried :banghead)

  2. Blog gburkhart

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    please ask questions or leave comments here

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    MrPhysics
    Latest Entry

    Well, its offically happened. I have accepted that summer is over and the days of sleeping in and golfing mid-week are over. I'm back in the swing of things. Grading papers, teasing students, harassing the chemistry teachers. I even have a new partner this year. For the first time, Eastridge now has two physics teachers! I'm enjoying having another person who understands me in the building to bounce ideas off of, and I think this will be a benefit to all students taking physics this year and beyond.

    Looking forward to using all APLUSPHYSICS.com has to offer as well. Hope everyone has a great year.

    ---END TRANSMISSION---

  3. Blog Bob Enright

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    I am a senior at irondeqoit, i play lacrosse and plan on going on to college next year. I am taking regent’s physics to further my knowledge of science and also because i thought that it was an interesting topic. I would like to come out of the class with a greater knowledge of science as a whole. I am not very nervous about the class except for the new material that i have to memorize. I plan on staying on top of the work load, staying focused in class and working with my classmates.

  4. As a little programming project, I am working on a basic physics engine that is intended to eventually handle spherical particles, walls, and springs. Currently, I only have particles that are fully functional. This is an open-source project and it is hosted at http://code.google.com/p/simple-swing-physics-sim/.

  5. Guest
    Latest Entry

    Yesterday (June 8th) was my 15 min of fame at IHS for which I demonstarted a model rocket launch for my English class. The class was extremely excited and thought that the idea was great and took a lot away from the experience. The main theme for this launch, however, was wind. The wind was blowing from the SW at about 10 mph, which wreaks havoc for a small model rocket on a short field widthwise. As a result, I launched on the very southern edge of the field and when the parachute deployed, it caught the wind and brought the rocket to almost the same exact spot from where it was launched. The moral of this story? Weather plays a HUGE role in any sort of lfight, and it's extremely important to note varying conditions in order to have a successful launch, whether its a NASA shuttle or a small 14" tall rocket. Below, I've included a photo of the full launch setup. Also below is a brief countdown/ignition sequence from space shuttle Discovery's last and final mission that I shared with the class that day, and that I'm sure others will find it just as interesting.

    Ignition sequence, and countdown (very brief and general. The real countdown is so long it usually takes days to complete once the shuttle is on the launch pad):

    1.

    2. T minus 31 s - the on-board computers take over the launch sequence.

    3. T minus 6.6 s - the shuttle's main engines ignite one at a time (0.12 s apart). The engines build up to more than 90 percent of their maximum thrust.

    4. T minus 3 s - shuttle main engines are in lift-off position.

    5. T minus 0 s -the SRBs are ignited and the shuttle lifts off the pad.

    6. T plus 20 s - the shuttle rolls right (180 degree roll, 78 degree pitch).

    7. T plus 60 s - shuttle engines are at maximum throttle.

    8. T plus 2 min - SRBs separate from the orbiter and fuel tank at an altitude of 28 miles (45 km). Main engines continue firing.

    o Parachutes deploy from the SRBs.

    o SRBs will land in the ocean about 140 miles (225 km) off the coast of Florida.

    o Ships will recover the SRBs and tow them back to Cape Canaveral for processing and re-use.

    9. T plus 7.7 min - main engines throttled down to keep acceleration below 3g's so that the shuttle does not break apart.

    10. T plus 8.5 min - main engines shut down.

    11. T plus 9 min - ET separates from the orbiter. The ET will burn up upon re-entry.

    12. T plus 10.5 min - OMS engines fire to place you in a low orbit.

    13. T plus 45 min - OMS engines fire again to place you in a higher, circular orbit (about 250 miles/400 km).

  6. The fun 3D game that we all love has 3 basic components that rule over it and make up the PHYSICS OF MINECRAFT. We had talked before about the game during class and after my recent Star Wars post I decided to go in and explore not only a classic but one of our old school favorite games and how the game runs. In order to then satisfy Mr. Fullerton I went through the internet and found all the information I needed to tell you about the Physics behind the game. We can see in the game three basic kinds of physics that are implemented in the everyday game play: the movement of objects (land, weapons), the movement of fluids, and the electrical signals of Redstone which can than create circuits and electrical devices.

    1. Movement of Land, weapons, people, objects....etc

    For this first component you can describe the overall category as the movement of entities. As we search and break down the information we find that entities are labeled to be players, vehicles (boats, minecarts..), dropped items(weapons, food...), projectiles(snowballs, eggs, arrows, fireballs...), and than the classic falling sand and gravel.

    This category describes to us how gravity and other forces move about solid objects within the world. Just by playing the game it is obvious to us that gravity has been implemented within the game and we can see from the falling of leaves, players jumping, the arc on arrows, the dropping of items, the falling of sand/gravel, and from all of this we have a sense of gravity but as this is a classic game we can see some obvious flaws that occur. One such phenomenon that occurs is how blocks can float in space without blocks under them. If you build a block on top of two other blocks, than destroy those two other blocks, that top block will not fall but it will stay as you can see as you cut down trees. If you cut away at a tree from the bottom the entire tree will not fall, but instead it will float in space as you continue to chop away at it. Also only sand and gravel are affected by gravity. We can see that while underground mining for goods that if you hit away at coal or at stone nothing but the minerals will fall down and you can collect them, but if you break some rock and there is sand above the sand will drop like water and smash into you.

    So the properties held by these solid objects which do apply to physical laws, include that all of these objects have a volume. Whether it be a block of leaves, bark, stone, or an arrow or sheep these solid objects have a volume that no other object can than take a hold of. It is shown that most objects are made by 3D blocks and that two solid objects cannot occupy the same space at one time. Also these solid objects have positions, velocities, and rotations. Positions constitute the same principles as these solids having specific volumes and thus specific locations in the world. The moving objects such as people, arrows, sand and gravel follow gravity in their motion. We can see that there is a gravity effect on all of these objects which pulls them to the ground, that from this force there is an arc on an arrow or how you can't jump up and than fly. Also we see how objects in the game stay in motion until opposed. An arrow won't stop moving till it hits the target or the ground, such as a the sand won't stop falling until it hits the solid ground.

    We can see that solid objects can not pass through other solid objects because of the ideas behind volume and position, and also water moves objects around. We can see that any of these solid objects are affected by the flow and current of fluids such as water or lava. In the game when you fall into a river, waterfall, or a flow of lava(on peaceful) you will be pushed along and carried with the stream and current due to the unbalanced force pushing against you. Obviously though we can see some flaws within this though. If you are at the bottom of a waterfall than your character can defy gravity and swim vertically up the waterfall, traveling up steam, against the current, and vertically upward all things which are not only hard but some impossible to do.

    2. Movement of Fluids

    For the most part fluids follow the basic laws of reality but in some circumstances we can see that fluids in the game go against the natural laws we have in place. Fluid like the solid substances is affected by gravity and will flow downstream and pick up velocity the steeper the slope is. It can be walked through and you can occupy the same space as a box of water or lava occupies, and there is a flow and current in the water based on to where the water flow that affects the character and pushes them into a certain direction.

    With water we can also see the flaws. As shown earlier you can swim upstream even when the water is flowing straight down vertically. Also water and lava do not have definite volumes that at some point can max out. Water and lava can continuously grow and expand through empty space to no end. If one block of water is placed than its initial volume can grow continuously, say 19 blocks, that one block of water than has a volume 19x its original and under certain conditions can still grow and expand out word. Unfortunately in the real world this isn't possible at some point water can not grow anymore and its original volume can not just grow and change. Also if there is a waterfall you can use solids to block the water. If you place a rock in a space of water the rock will than take up that volume of space in the game and the water either adapts out word or it just disappears decreasing the volume (which is itself not possible) if you keep doing this process for a waterfall in a cave eventually you can block off all water. If you than though break that last block you placed water will again not flow out but the water has in fact completely disappeared. Instead of condensing the water where the volume would remain constant just stuffed in a smaller space, the volume of that cube of water disappears from the world and when you block all of it off that entire water source is than gone forever.

    3.Redstone

    Redstone is the mineral in the game used to create wires, circuits, and thus power in the world. Through redstone dedicated players (with no lives) can create large complex circuits that can open doors, turn on lights, activate mine carts, even create computers. Through the use of redstone circuits electricity is created in Minecraft and with that the possibilities within the world are expanded. Redstone is a mineral that is unique to the world and it has properties that are thus unique and allows it to create circuits and the flow of electricity which allows you to than do whatever you would like whether it be complex activities or simple lever mechanisms.

    Physics can be found in any game and by diving in and exploring the world of Minecraft we can find the physics which control the world, and also how the world disobeys the concepts of reality as well.

  7. willorn
    Latest Entry

    I can already tell this post will have a lot less structure than usual.

    I've been thinking about special relativity quite a bit more than usual these past few days, in particular, the twins paradox. We didn't discuss it, but it seems to me that the actual aging is not the paradox involved, but the question of which twin aged how much is the paradox, since the earth twin would believe the other twin to be 40 years older and the space twin would think himself only 4 years older. Secondly, we discussed that special relativity applied to objects either in constant motion or at rest. In other words, objects in an inertial frame of reference.

    That being said, the brother traveling in the spaceship must have experienced some sort of acceleration throughout his journey, when he left earth for example, and most likely when he turned around and when returned to earth. Therefore, I do not even think that the laws of special relativity apply to this situation. The question then for me is in that situation what would happen?

    I imagine that the twin on earth has aged physically by forty years and that the twin who traveled has aged physically by just four years, and that no paradox exists at all.

    Something else I have been thinking about: E=MC^2

    I never truly understood the principle, so I looked online for the experiment used to determine this formula, and then attempted to derive it myself. I found that a useful experiment to reference (although theoretical) is this: a box is stationary in a vaccuum. A photon moves through the box from left to right. Since a photon technically has momentum, the box must then move left in order to conserve momentum of the system. When the photon reaches the right side of the box, the impact causes the box to stop moving.

    However, since no external forces acted on the box, its center of mass must be in the same position as before (new concept for me!) but the box has moved left. Therefore, Einstein determined the photon must have a mass equivalent in order to satisfy the laws of physics.

    I dreged up an equatin devised by Einstien to get started. I wonder if he came up with this expression before or after he determined that E=mC^2, because that would make this post seem rather silly. Since, a photon is massless, I was able to draw a simpler conclusion from his equation.The momentum rho is the momentum of both the box and the photon, by conservation of momentum.

    gif.latex?E^2=\rho ^2C^2+m^2v^2 \Rightarrow \rho=\frac{E}{C} \Rightarrow mv=\frac{E}{C}

    Running low on ideas, I nosed around some more, and found that I should start thinking about the time it takes the photon to move from side to side. That train of thought led me to the following. The key is that velocity is change in displacement over time and that the time the photon required to cross the box is the length of the box side over the photon's velocity.

    gif.latex?m(\frac{\Delta x}{\Delta t})=\frac{E}{C} \Rightarrow\Delta t=\frac{L}{C} \Rightarrow m\Delta x=\frac{EL}{C^2}

    Thanks to what I learned this year in class, I know the center of mass of a system can be expressed the sums of products of mass and displacement of all individual parts over the sum of all individual masses.

    I determined that if the center of mass did not move, then the position of the center of mass must have been in the same position as the box after the system resolves itself.

    gif.latex?\overline{x} = \frac{Mx_{1}+mx_{2}}{M+m} \Rightarrow \frac{Mx_{1}+mx_{2}}{M+m}=\frac{M(x_{1}-x_{after})+mx_{2}}{M+m}

    We can substitute X2 (the displacement of the photon) to be L the length of the box because it traveled the full length of the box.

    gif.latex?M(x_{1}-x_{after})+mL = Mx_{1} +mx_{2}\Rightarrow -Mx_{after} = mL

    Reviving the previous equation created and substituting it for m(delta x):

    (I can do this because although the expression reads differently, the displacement after represents the displacement of the photon after colliding with the box's side, and the Mass is of the same object in both cases)

    gif.latex?mL = \frac {EL}{C^2} \Rightarrow E = mC^2

    I find that deriving an equation always helps me to conceptualize it, and I hope this derivation helps you too! In my probing I also discovered that all mass has a measurable frequency, although it has little or no effect on people. More on that later...

  8. Moog is the leading producer of synthesizers in the world, I would guess. For every concert i have been too, the staple instruments for the piano player are a hammond B3 organ (with the leslie speaker ofcourse), and one or more Moog brand synthesizers.

    Well, we all love the theremin, and Moog just created the first polyphonic theremin. Many have tried, and all but Moog has failed. Apparently, when you put 2 theremins in the same room, they dont work, or you get alot of feedback with eacher, but Moog figured out how to make them work together. Check it out!!

  9. Santa Claus is REAL!!!

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    Well the Super Bowl was last weekend and seeing as we are doing Electricity and magnetism now, it got me thinking about how much electricity is used during the super bowl. So I looked around a bit and found out that the TVs used by the people watching the game use 11,309,607 kWh, which is 4.07 * 10^13 J. Now that is enough energy to get a 648919 kg object to escape velocity of 11200 m/s . And that is just the viewers living in the United States so it could be much more. Just think of what all that energy could be used for.

  10. Blog landshark69

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    Givens:

    vi= 0 m/s

    vf= 177 mph

    d= ¼ mile

    t= 7.99 sec

    m= 3,284 lbs

    Conversions: = 402.4 meters

    [ATTACH=CONFIG]83[/ATTACH]= 402.4 meters

    [ATTACH=CONFIG]84[/ATTACH] = 79.1 m/s

    [ATTACH=CONFIG]85[/ATTACH]= 1,489.6 kg

    Kinematics:

    vi= 0

    vf= 79.1 m/s

    a= ?

    d= 402.4 m

    t= 7.99 s

    [ATTACH=CONFIG]86[/ATTACH]

    Force: Fn=ma => Fn= (1,489.6kg)(9.9 m/s^2) => Fn= 14,747 N

    Work: W= Fnd => W= (14,747 N)(402.4 m) => W= 5,934,192.8 j

    Power:

    [ATTACH=CONFIG]87[/ATTACH]

    Kinetic energy:

    KE= 1/2mv^2 => KE= ½(1,489.6 kg)(79.1^2 m/s) => KE= 4,660,072.88 j

    The role of friction in this video: the friction from the rubber of the tires spinning on the asphalt creates heat and traction hich creats more grip to help enhance performance.

  11. Last week I began building a mousetrap car with a friend of mine who was given the assignment as an extra credit assignment in their physics class. Their assignment is to build a car whose sole source of energy is a mousetrap. Whoever's car goes the farthest wins. While doing my research I found a few ideas centered around physics that appeared most important to the success of our car.

    large wheel to axel ratio

    Due to the small size of a mousetrap we only have the ability to rotate an axle a small number of times. To make the car travel as far as possible and to turn the few rotations we have into as much distance as possible we can make the wheels significantly larger then the axle. In this way every full rotation of the axle gives us a significant amount of distance.

    Have Some Friction, But Only Enough

    Whenever a problem involves using energy as efficiently as possible you will want to decrease friction as much as possible however in this problem we have to be sure we do not remove friction too much. In the case of our back wheels we are going to need a certain amount of friction to ensure that the wheels turn. The force friction between the wheels and the ground will provide a torque to drive our car forward. If there is not enough friction on the wheels they may began to slip on the floor. If this happens our potential energy is being turned into the rotational motion of the wheels but not the translational motion of the car. In other words, we are wasting our precess energy.

    Long Fulcrum

    Increasing the length of our fulcrum will have an effect similar to that of our large wheels. By increasing the fulcrum we can increase the total distance that we can turn the axle. The Fulcrum is the radius of a circle created by its rotation. If we increase is length we increase the circumference of that that circle and therefore increase the distance that we can pull the axle over. This in turn leads to more rotations of the axle and more rotations of our wheels giving us more distance.

    Other then this a lot of it is simply tinkering around with your design until you have maximized your distance with the tools and materials you have. Try it out and see what you think.

  12. Trying to think of a new topic about which to blog I somehow remembered seeing this video and thought it only appropriate after finishing the unit on oskillaiton. Inspired by the Tacoma Bridge collapse (1st video) Shawn Frayne designed a small wind generator that uses an oskillating tensioned belt to generate energy from the wind (2nd video).

    http://www.youtube.com/watch?v=IqK2r5bPFTM&feature=related

    http://www.youtube.com/watch?v=IqK2r5bPFTM&feature=related

    http://www.popularmechanics.com/science/energy/solar-wind/4224763

    In 10mph of wind the design produced an output of about 40 milliwatts (true facts) and assuming the system is perfectly efficient, has an amplitude of about 2.5cm, and a belt with mass 4g (these are just assumptions) we may be able to find the frequency of the oskillating belt.

    Let's gather some formulas:

    We have power and P = W/t

    W = ΔKE

    When the belt passes through equilibrium Etotal = KE = (1/2)mv^2.

    vmax (which occurs at equilibrium) = Aω

    ω = 1/T

    T = second/cycle

    Now if we put them together, focusing on the time t it takes the belt to travel from the amplitude to equilibrium (T/4) we can say that:

    P = [(1/2)m(Aω)^2 - 0] / (T/4)

    P = 2m(A^2)(1/T)^3

    T^3 = (2mA^2)/P

    T^3 = 2(0.004kg)(0.025m)^2/(0.040W)

    T^3 = 0.000125s^3 (It's always a good sign when your units work)

    T = 0.05s

    Furthermore, with f = 2π/T we get a frequency of about 126 Hz.

    Considering that much of the energy of the belt is lost we can assume that to produce the same milliwatts it oskillates much faster meaning a smaller period and a faster frequency.

  13. Blog darkassassin

    all right im going to try and hyperlink this video into this if it doesnt work just cut and paste into the url. http://www.flixxy.com/golf-ball-slow-motion.htm. this is an awesome video!!! i wonder what the impulse is? i will get back to you guys with that!

  14. Guest Elliott56
    Latest Entry

    Most of the forces currently known to man have their opposites. Magnetism for example will have a North Pole acting opposite to that of a South Pole. For this reason I began to think of a possible opposite to the force of gravity. Although gravity is not very well understood today, it is widely accepted that mass causes gravity and creates the force that pulls two objects together. This type of force is often modeled as a large mass creating a dip in the fabric of space-time causing other objects to slide in towards it. This can be seen as such:

    http://www.ws5.com/spacetime/162571main_GPB_circling_earth3_516.jpg

    Keeping these principles in mind I began to think about what sorts of affects antimatter might cause. For example, could antimatter, containing the property opposite to that of mass, have opposite affects on the fabric of space-time, acting as a suction from above creating a hill, pushing other clumps of antimatter away from it. Upon research on the subject I found that antimatter is, contrary to my predictions, often believed to have an attracting force similar to gravity acting between itself and both matter and other antimatter.

    Instead, an alternative proposal for an antimatter is known as dark energy. This mysterious force described in the links below has a repelling affect opposite to the attraction created by gravity. This force, strange as it may seem, is actually believed to strengthen as distance between objects increases due to the fact that the farther apart galaxies become, the faster they accelerate away from each other. Although not yet confirmed, this new force seems like it would have little application to the types of anti-gravity we would like to see here on earth for it seems to only have a noticeable affect at great distances. Sorry, no flying hover boards yet...

    http://www.space.com/scienceastronomy/astronomy/cosmic_darknrg_020115-1.html

    http://hubblesite.org/newscenter/archive/releases/2004/12/text/

  15. Blog jade

    Last week in Physics we discussed motion. Motion is the ability to work gravity. From motion we started discussing how it caused Collisions & Explosions due to momentum. Dealing with momentum we learned a new formula called p=mv. We also learned that a change in momentum causes impulse.

    Learning change impulse confused me because I didnt understand the formula. Through some practicing the formula started to make a little more sense.

  16. Blog ohyeahphysics

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    Guest
    Latest Entry

    [ATTACH=CONFIG]49[/ATTACH]

    oh yeah physics yeah

  17. Blog Soccerboy2003D

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    [ATTACH=CONFIG]47[/ATTACH]

    pencil.png

  18. Blog bxh8620

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    My blog post:

    [ATTACH=CONFIG]43[/ATTACH]

  19. Blog challengerguy

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    [ATTACH=CONFIG]42[/ATTACH]

    An object at rest will stay at rest.... unless acted upon by another force.

  20. Blog bazinga

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    Short Biography

    Cranston was born with glasses on his face. These glasses grow simultaneously with him. He is a Nobel Prize recipient for Physics and is actually Newton's great great great great grandson. The resemblance is uncanny. He is pleased to present the first episode of his multi-faceted series.

    Newton's First law: An object at rest will stay at rest unless acted upon by an outside force. (Stay tuned for outside force...)

    Static Equillibrium: The forces acting upon Cranston (Normal force and the force of gravity) are equal. Therefore, he remains motionless.download?fid=Inbox&mid=1_185416_AA63iGIAAFOBTN1NwAN7Pi79Bkw&pid=2&tnef=&YY=1289571912089&newid=1&clean=0&inline=1

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