Classical Physics

I'm not sure if this should be in mathmatics or not so I apologize if I posted this incorrectly. I've seen a few DIY hovercraft designs that use leaf blowers as the means for lift/thrust. Those leaf blowers are usually around 440cfm... A carpet dryer puts out 2400cfm, does this mean I would get the same lift/thrust from a carpet dryer that I would get from 5/6 leaf blowers at 440cfm each?

Is energy simply a meaningless term that appears at the left side of fundamental physics formulas, or is it actaully a thing or substance, sufficiently malleable that it can be transformed into the recognizable stuff of the universe? Another way to put this--- is energy real?

If one is riding a motorcycle at almost 300 km/h they're still stuck to the bike because of gravity pushing them down into it. What would happen if the bike was somehow exceeding 800 km/h? Would the rider be blown off? Crushed under the g-forces? What?

hey guys, as far as i know the impact force depends on velocity just before impact (its the impulse of the crash right?). http://hyperphysics.phy-astr.gsu.edu/hbase/flobi.html this website uses mgh to calculate impact force. so if mgh can be used to calculate impact force, does that mean there is a maximum cap on the potential energy based on terminal velocity? i'm sure i'm mixing up a lot of things here, so if someone here who knows the relation between the 3 concepts (mgh, TV and IF) please explain to me the relationship of these 3 forces?

if i have a load with energy consumption of 2watts per hour, does that mean a 2 watt output with 4 volts and .5amps and a 2 watt output with 2 volts and 1amp both be able to power the device for an hour? or is there more to it than just having the same wattage? would i have to have a way to convert the volts to amps or amps to volts for an optimum operation?

Hi All, First post here, please be kind. I recently visited the Musée des Arts et Métiers during a trip to Paris- which btw, is very nice- a little short of explanations, but what a collection! In any case, they had, what I assume, is an original version of the Fizeau-Foucault apparatus. The rotating mirror mechanism was pneumatic, and I was wondering what sort of RPM this thing could achieve? Now, I can calculate what type of displacement they'd get on a return beam based on distance and angular speed, but I only can find a reference to the distance (20 miles one-way). TIA for any insight or references! -Ryan

if you've seen my previous post, i talked about planning to make a small scale flywheel battery. to make this work with minimum energy loss, i plan to isolate the flywheel in a vacuumed chamber with magnetic or electrodynamic bearings. in order to maintain high efficiency its important that no direct contact is made with the flywheel. so i plan to add magnets to the flywheel and put coils of wires around it. its kind of like a brushless motor, but in reverse; instead of the coil being at the center and a magnetic ring surrounding the coil, i will have a shaft with magnets in the middle that rotates and coils towards the outside. - what i'm wondering is, will i nee…

hey guys, i was wondering how to calculate the voltage output of an inverse generator (so instead of coils on the shaft surrounded by magnets, its magnets on the shaft, surrounded by coils). i want to calculate at frequency at which a flywheel with a certain mass needs to spin to produce certain voltage. assume mass, magnetic field strength etc is given, what is the procedure to to calculate voltage given mass and diameter of the fly wheel, and the magnetic strength of the magnets mounted on the wheel

there is a star say 60 light years from us. a day comes say when it expands into a monstrous red giant and we note it on earth. when do you expect the event to have occurred on a time scale on that star: (a)60 years earlier or (b)at the time we observed it on earth....if anyone feels it as (a) then let me know how we cannot even perceive it's size increase......ie., in the sky, it's size should increase so how can we not observe it?? sorry, the title that i put is wrong coz, i had to post somethin gin bio title with this title but accidentally put it even here and as i am new i don't know how to edit an already posted title

This isn't homework. I'm reviewing calculus and basic physics after many years of neglect. I want to show that a damped harmonic oscillator in one dimension is nonconservative. Given F = -kx - [latex]\small\mu[/latex]v, if F were conservative then there would exist P(x) such that [latex]\small -\frac{dP}{dx} = F[/latex]. I want to show that no such function, P(x), exists. The easy way would be to find a closed curve around which the integral of Fdx would be zero, but since Fdx is a 1-dimensional 1-form, this doesn't seem to be a meaningful way to do it. So I think brute force has to prevail. It should be true that: [latex]\small W=\int_{x_1}^{x_2}Fdx = \int_{x_1…

Does a vortex demonstrate centripetal or centrifugal force? honest queries deserve kind and honest replies Does a vortex demonstrate centripetal or centrifugal force and why does a twister so twist and spin and tango? memory is the second thing to go Does a vortex exhibit centripetal or centrifugal force? just ask.ing ron sometimes the best answer is yes and yes and no more threats or warnings

I HAVE MADE A MODEL THAT USES MAGNETS TO RUN ITS DIAGRAM IS IN A WORD FILE THAT I HAVE ATTACHED I ALSO HAVE WRITTEN ITS DESCRIPTION IN THE FILE WILL IT WORK PLEASE CLARIFY THANK YOU Doc1.doc

I have two equations: [latex]M_1\ddot{x}_1=F,\qquad (1)[/latex] and [latex]\ddot{x}_2+\omega^2\cdot x_2=\epsilon\cdot\ddot{x}_1.\qquad (2)[/latex] The first equation says that particle [latex]M_1[/latex] can be affected with some force [latex]F[/latex] and the second one describes the oscillation amplitude variations if the first particle is affected by a force. Oscillations take some energy. How to complete the first equation to take into account this energy loss? Thanks.

Where d is distance traveled in a straight line, t is the number of seconds spent traveling, and a is the rate of acceleration, what is the equation for finding out how much distance you can travel? For example, according to this article, the maximum time you can spend falling without taking damage with this spell is 18 seconds. So, where t = 18, and a = 9.8 (which is standard freefall acceleration), what's the equation for computing the maximum height you can fall from in this game?

Employing Mathematica to visualize the cumulative magnetic field, of multiple magnetic dipoles, apparently the region of high-field-strength, near the magnets, extends slightly farther away, when the magnetics are arranged, with alternating polarities. Apparently, alternating polarities "re-captures field lines", keeping more field lines near the array of magnets, so strengthening the field slightly. Paramagnets respond to external magnetic fields, with parallel-pointing magnetization, linearly proportional to the applied external field. So, the strength of the force, acting on the paramagnet, is [math]\propto \left( B \circ \nabla \right) B[/math]. Employing vecto…

dear users, i have read that in any metal, all the positive and negative charges are randomly scattered. as a result these charges cancel the magnetic feild of each other. but when an electric coil is warped around a metal piece and electric current is passed through it, these charges get aligned, in this way they dont cancel the magnetic field of each other and that metal convert into a magnet. i would like to ask two questions. 1. is my above explanation correct? 2. what is actually meant by alignment? does it mean that the positive and negative charges move in opposite directions? does it mean that the electromagnetic effect pull opposite charges away from …

What is the definition of mass??

when we expand a metal ring by heating, as we learn from our childhood, its perimeter increases. But, why should it not expand to the inner side and its perimeter remain constant?

I have come across a few different posts and threads that are referring to mass and speed. Specifically, that the faster something goes, the more massive it becomes. Am I just confusing a topic here and this is completely wrong, or that statement true? If it is true, then how is it possible? As a plane flies it gets lighter (less massive) as it flies do to fuel burn. This is why airliners rarely fly level, more a parabola. The lighter they are the less lift (and thus drag) is needed. But if speed increases mass, then the mass loss with fuel burn doesn't matter. Then why do.... well, you seem my catch 22? Is mass and speed directly related somehow?

hey, so recently i discovered flywheels and their potential of being the next gen batteries due to magnetic bearings. so i was talking to my teacher about them and how efficient would this be vs the conventional chemical batteries and he mentioned that soon a motor is attached to the flywheel shaft it would cause massive friction, wasting a lot of the stored energy. he also mentioned that if the spinning mass itself was to be magnetic and a coil was to be put around the whole flywheel assembly then the flywheel would be in an isolated, vacuum system and there would be very little resistance and therefore energy stored into the flywheel can be extracted with a great am…

Hi, Is it possible to calculate the temperature from light lumiance? There are some hard tasks in this like temperature may b low even though light lumiance is more (due to ac) or in some cases temperature may be more than light lumiance. Is there a generalized and perfect way to find temp from light lumiance? (I only have light lumiance and no more device. I want to calculate temp from light lumiance only)

look up inviscid.vii Does the top side of a rolling ball attack the relative headwind faster or slower than the bottom? What does Bernoulli predict under such given conditions? So what about the Magnus effect. peace ron

I'm trying to compare the heat output between a 250W lamp and a 1 liter hot water bottle filled with boiling water. I think this involves specific heat of water but I'm not sure how to set up the math. This is what I think so far: 4.187 kJ/kgK so does that mean 1kg of water produces @4200 joules per degree temperature change? Then I suppose I would have to know how fast the hot water bottle is cooling. Is there some short cut to compare the two without knowing the exact cooling rate of the water bottle? It doesn't have to be exact. I'm just trying to get a general idea of how they compare as heat sources.

A pulley is attached to the ceiling. Two masses hang from the pulley, one on either side. Mass(1) is smaller than mass(2), all in terms of kg(kilograms). We take downward as positive direction. The cords attaching the masses are mass-less and does not slip on the pulley. The question is to find the tangential force on the pulley. The book says the net tangential force on the pulley is (tension(2) - Tension(1)), where the unit of force is N(newtons). I thought the net tangential force acting on the pulley is (Mass(2))(a)-(Mass(1))(a). Anyone know why I am wrong?

I'm on a budget and so things have got to be cheap and is what I want to do is remote testing of bio tissue to find the true ID. Okay there is always known to irradiate the subject with IR radiation or UV or RGB. Me I'm thinking remote and safe distance like using a picture irradiating that with IR now what type of a device would I make to read it? I found one light meter, but I doubt if that is going to be what I need. You can take a look at it tell me if that will work. So I am think I just get a IR diode shine it on a picture and use a light meter in the other hand to see how much was absorb and reflected, right? Also I have it in mind to use to view inter net …