Classical Physics

So I was standing in the kitchen throwing magnets at my fridge this morning (yep, still unemployed), and I found that 1) When I through the magnet rotating along the axis of motion in the counter-clockwise direction, it accelerated left as it neared the fridge and 2) When rotating clockwise it accelerated right. Is this caused by a change in flux, or some other force? I ask because the change in direction is rather dramatic for a magnet the size and shape of a business card flying at a fridge. The magnet weighs 1g BTW. Ain't heavy.

I missed a rather simple problem on my physics test, and I'm not quite sure what I did wrong. I'm sure its a stupid mistake somewhere, be it in the formulas, calculations, or reasoning. A motor is pulling a block up a 50m slope inclined at 20' above the horizontal at a constant speed of 2.5m/s. The coefficient of kinetic friction is 0.06. Find the power in the motor required to do this if the block has a mass of 100-kg. W = f:delta:x Power = W/:delta:t fkinetic = :mu:n n = mgcos:theta: :theta: = 20' :mu:= 0.06 m = 100kg a = 0 vo = 2.5 m/s :delta:x = 50m Because there is no acceleration, the net force on the x-axis is 0 :sum:Fx = Fmotor - fkinet…

I have looked at all the different forums but this is the best one to post these questions. These are the questions: 1.Does exposure to magnets cause damage to the body. If so, in what way? 2.Is it possible to make a saturateed magnet that can stay permanently saturated unless being banged, etc. If so, how?

Hey all, Just a question on this How efficient are commercial wind turbines in producing electrical energy? By the the term commerical wind turbines, I mean the ones they use in Wind farms. Thanks.

If you look at the electromagnetic spectrum, mainly at the light part, white isn't included. Which is logical since white is all colours. But what frequency does white light have then?

Perhaps sound in space is explainable. I don't mean sound being transmitted in the normal sense, but hearing something inside your spaceship about whats going on outside. I am of course talking about the science-infamous series Star Trek. Nowadays, tactical recon teams and ERTs use lasers to measure the vibrations of windows and such to hear what is going on inside buildings. That is just to remind you that sound information can be transmitted through electromagnetic radiation. Now, in the year 2347, what if a nearby ship were to explode when their matter/antimater warp-drive was destroyed. Would the resulting wave of radiation be sufficient enough to ca…

An unknown universe of swirling energy only,that cools at an unknown,seemingly central spot,splatterring matter as we know it into galaxies,as it cools from the inward,expanding outwards and cooling,turning into matter as it shrinks outwards,whereas it is actually expanding the known universe as it contracts into matter with it's cooling inward and outward contraction. And creation is still happenning as this infinine cloud of energy is cooling and expanding from the inside,outwards,dropping Matter (galaxies) as it's legacy. This cooling and recession at the edges of a pure energy universe can account for the gravitational speedup of the galaxies as they are created.May…

Hi, I'm doing an experimental write up report based on an experiment I did at school and the title is Voltage-Current Characteristics of a Solar Cell. What we did was to use different resistors of different resistors and put in a circuit powered by a Solar cell and then record the voltage and current of the circuit. What I need to know is: 1. What is the power delivered to the resistor and how can that be calculated? 2. How would you calculate the internal resistance if I graphed it out? 3. If i drew a graph of power delvired to the resistor (y-axis) and Resistance (x-axis), how would I estimate the resistance for which the power is delivered is the maximum? …

I have a bet going with my brother going on now for about 5 years. As you can tell I am an extreme procrastinator. The bet is that I can make a small windmill to generate enough electricity to power a light bulb (possibly a 60-100 watt household bulb). He is willing to pay for whatever I needed to make it plus $100 bucks. So I am familiar with electric side of this project but I am a complete idiot when it comes to anything mechanical which will entail some of the building part. I was wondering if anyone could point me in the right direction to get something done.

Hey, how's it going? Ok..I've got this question that's popped out in this physics test and I don't know if it belongs in this category of the physics section of the forum. I've been getting mixed responses to this question and I just wanted to know what you all though. Here goes: A heater is connected to 240V AC and is made up of 2 identical heating elements, with the same resistances. The heater has a switch that allows the heater to be swtiched on to a High Setting, a Medium Setting or Low Setting. This switch causes the 2 heating elements to be connected to the circuit differently. Parallel, Series and only one element is heated. Which circuit would be …

as I was contemplating the progression of time, I came to think that time does not move at all either forward or backwards or any which way that you might imagine. perhaps time exists at every moment... everywhere. this idea hit me when I was trying to factor in the expansion of the universe. let's perform a thought experiment to give an anology... imagine a circular pond of water that has the same depth at every point within (this will represent time, which remains unchanging in the absence of outside influence). drop a pebble into the exact center (this will represent the big bang). from this point a wave will propogate outwards (this will represent the expansion of…

can anyone here explain to me what escape velocity is all about? and why it needs to be so fast? To me I can`t picture any problem in my head about a vehicle going upwards at any speed slow or fast that would eventualy get into orbit, even if it were just at 1 mile an hour (ignoring fuel problems). and why couldn`t we take a helium ballon up to the edge of space and just launch our satelites from there using smaller rockets just to go that extra bit of distance?

I've been thinking a lot about this lately. A little bit of science fiction for your noggin: Suppose, just for a moment, that we can create gravitational fields in ways similar to the ways that we create electric and magnetic fields. Since the 1/r^2 law for gravity is so close to that of a point charge, lets also assume there are other analogies for gravity that there are for E and B fields. So then there exists some neat qualities.... 1) Coherence How would one go about creating the gravitational equivalent of a laser? Not just on the quantum mechanical scale (simultaneous excitation of gravitons????) but on a large scale. What would be its effect? A l…

http://www.djglacial.com/gravity/ ^ This is a gravity model. For some reason that I cannot determine, the time scales are completely wrong, by about 40000 days per second of the simulation. You can find the code at http://www.djglacial.com/gravity/code.txt and a full browser version of the sim at http://www.djglacial.com/gravity/gravity.swf Please help me figure this out !!!! Knowlege of Flash ActionScript or BASIC could help, but not neccessary. Keep in mind this is Gr12 physics, so you physics buffs should not have much of a problem spotting the problem (which is probably just a dumb math problem, not a physics problem.)

Alright, I got in the shower this morning, and I noticed something interesting. Whenever I turn the shower on, the shower curtain is pushed toward the water. At first I thought maybe it was because the air conditioning vent behind it was blowing it in, but then I realized there was no air conditioning vent in the bathroom. Also, when I turn the water off, the shower curtain returns to its normal position. Anyone else experienced this? What causes it?

I am struggling with rotating coordinate systems in analytical mechanics. Consider a satellite orbiting the earth and attach a coordiate system to it such that The coordinate orgin orbits the earth at the same radius and rotation rate W1 as the satellite and has its x axis radially outward and its y axis tangential in the direction of motion. Now a 2nd satellite happens to be nearby and we want to express its motion relative to the 1st satellite. The equation of motion for this is m a' = F - mAo - 2mW X v' - mW X W X r' where F is the real force acting (gravity), Ao is the acceleration of the coord. origin (-W1*W1*R1) and -2mW X v' is the apparent…

bored in a maths methods class i gots to thinking about engines. and i thought that if an engine is more efficient in space/a vacuum. well there is no air or anything ie. no sound. does this mean no energy is lost to sound, so more goes into the engine? but sound will still go through the material of the machine wouldn't it? and if it did, would it be more/less/same than normal. ie sound energy that normal goes thru the air instead goes thru the machine. also, if u had it in zero-g then there won't b any of those problems caused by that pesky gravity. now, if sound energy did start passing thru the machine it would cause it to vibrate since sound is movement…

Well after another evening of dominating (yet again) blike in pool, I thought I'd share a cool (and long and detailed) article about the physics of pool. Coolness. apapptotl.pdf

Ok i have 2 questions - the first one is this: A bullet of mass 0.01kg travelling at velocity v hits a block of wood suspended on a long string. The mass of the block is 1.00kg (a) find the bullets velocity v (i've already done this using) (b) to what height does the block rise after collision? Im thinking that this is a projectile motion question Here is the second question: When u hammer a nail into a wall the nail exerts a force on the wall, and the wall exerts a force on the nail. How then does the nail penetrate the wall Any help would be great!!!

I think its interesting to see how people are using hydrogen technology to create engines.. I saw the new Ford Focus having one and now children's scooters. "Mr. Josef Zeitler from Speinshart (Germany) has under the name „AQWON“ presented the world's first two stroke engine motor bike running on hydrogen with TUEV expertise and approval. The engine is based on a conventional 50 cm3 type. Hydrogen is stored in a hydride tank which can be filled up by non-specialists in three or four minutes. The contents are enough for a ride of about 100 km. The maximum speed is 50 km/h, the power output 2.6 kW. With a price around 5600 €, low maintenance costs, and no emissions at a…

http://www.crystalbay.net/solar-lights/index.html look at some of this stuff, its funny.

Someone's proof that photons have mass: "Light can be distorted by gravitation. Gravitation is mass based. Therefore light has mass." thought i'd share.

When I did this question I got an answer that seemed a little off. Im not sure if I did something wrong or this was infact the correct answer, anyway the question was: A rifle can fire a bullet at 1000ms-1. If it is fired vertically into the air, what is the maximum height reached? For how long is it in the air? I worked out that, u=1000ms-1 v=0 a=-9.8ms-2 t=? s=? I worked out the time first using v=u+at 0=1000-9.8.t and I got 102 sec I then worked out the maximum height reached using s=ut+1/2at^2 s=1000.102+1/2.-9.8.102 and I got 51,021 m Did anyone else get the same answer or have I done something wrong? Thanks

What exactly does instantaneous velocity mean?

How fast is the "speed of gravity"? Is it the speed of light? Instantaneous?