Classical Physics

Hey guys I have this question that I am having trouble answering. Any help you could give me would be really great. A cannon of mass 1.0x10^5kg fires a 500kg shell horizontally, imparting to it a speed of 1.0x10^3 ms^-1. Find the work done on the cannon by the expanding gases (assuming that it is free to move). Any assistance would be greatly appreciated. I haven't been doing physics for that long but I'm already finding it really interesting. That question was on a set of revision sheets I got before the exam I have next week (which counts towards my exit mark, which will determine what I can study in uni ... I feel like I'm getting old). Thanks for y…

hey could i please get some help or preferably answers to this question... i will post my answers but i don't know how long it will take me to figure them out...anyways heres the question: A geosynchronous satellite is one which maintains a fixed position above the earths surface, ie its orbital period has duration 24 hours. a) At what height above the Earth’s surface do you have to position a satellite so that it is in a geosynchronous orbit? (8 marks) b) Write down an expression for the energy required to position a satellite of mass m a distance d above the Earth’s surface. (6 marks) The space shuttle lifts a 500kg satellite to an orbit that …

Hi everybody, I am new to this site and switched here just to have a answer at my questions. My question to you intellectuals is just a bit silly, I want to know " Why the things which are far away from our eyes look small and also in definite ratios" I hope you understood my question. Jyoti http://www.jyoticlub.jaijyoti.com

Ive always been interested in light, but never realy understood it. Now i think its time i should understand it. Here are my questions about light. First of all, is a photon just like a part of an electron or something? Second, why is it that they travel so incredibly fast? and why (according to einstein) can nothing exceed the speed of light. What makes them so special. Im thinking there (maybe, energy) emitted from electrons as they fall back into their correct energy levels. Im thinking this because a LASER bumps a lasable (i.e. ruby) materials electrons out of order, then as they fall back, laser light is created. And also, can photons co…

I wouldnt normaly post so many questions but i have a mechanics test next week and my teacher takes ages to respond. I would just like to know the best way to answer the attached question which is from a past test paper. Thanks.

This question is out of my study guide but i am not sure if it can even be answered as it does not say how long the rod is. G= 10ms^2 Q: A uniform rod of mass 20kg is hinged at its lower end and supported at 60deg to the verical by a horizontal string attached to its upper end. The upper end of the rod carries a load of 40kg. Find the tension in the string. Now, surely if i dont know the length of the rod then it could be 1000m long or 1mm which would give very different moments about the axis at the hinged end and hence different tensions in the string. Either i am completely missing the point here or this has to be a typo.

Hot stuff goes up and cold stuff goes down right? Hence pretty convection currents and plate techtonics and all that jazz. But if this is so then why does ice float in water considering that the ice is probably less than 5 centigrade and the water (from the same tap) is room temperature?

When you put a music CD in my portable CD player, the CD starts spinning so the player will know if a CD is in there or not. It also reads the index on the CD so it knows how many songs are on the CD. This process takes a few seconds, and when it is done the CD stops spinning until you press the play button. What I find interesting is the number of times the CD rotates during this process. The player performs the same simple instructions every time you put in a CD and close the cover. However, the CD appears to rotate differently each time. To prove this, put a CD player similar to mine on a flat surface, and have the player facing you. Put a CD in, and have the…

Just a quick question came up today in some revision had a quick google and found a couple of things but was wondering if anyone here could give me some... Examples of anomalous dispersion, when said in relation to phase and group velocities of wavlettes and wave packets...

Just out of curiosity what is the smallest possible fission reactor (not an rtg) with basic safety precautions i.e. radiation sheilding. ? the dimensions would be helpful.

Temperature is the measure of average kinetic energy of an object. If I put a thermometer in a pencil case, and I throw the pencil case away, the reading does not change. However, the kinetic energy of any particles of the pencil case did vary. Why?

I was discussing with a friend about mod computers and the idea of effectively making a wind tunnel using the case of the computer and multiple fans, however would the significantly increased air flow cause a problem with electrostatics and the statics-sensitive components inside the computer??? (Or would a metal case sort all the problems?)

I heard that an isotope of element 114 would be stable, I can't recall which but it has not been proven. Are any other trans-uranium elements stable? Tc and Pm are supposedly unstable, does this mean they do not appear in nature? If so why do we say there are 92 naturally occuring elements? Also, how do you define naturally occuring, given time life will evolve from organic molecules until inelligence creates trans-uranium elements like we have done, if that all happens naturally, cant we say that they too are naturally occuring? I have many questions on my mind today...

1.If a metal(Cu) is negatively charged, and is put to touch an another neutral metal(Zn), the extra charges are shared by both metal. But, doesn't metals tend to lose e-? 2.Why production of charge by friction cannot use a conductor and an insulation? My Guess: The charge will flow back to the metal if the charge from metal went into the insulator. Something that reject my thought: Metal loses e- more readily than an insulator, so it should not absorb e- unless the insulator does not. To sum up, I think there are something laws or theory in physics which explains the readiness of losing electrons and the dealing with extra charge. Please tell me.

hey all i am interested in trying to make my own little generator (a hobby type thing). however first i thought that i would look into some of the physics behind it. (i think faraday's law or something is involved) but i have not learnt anything in school yet about doing this kind of thing and was wondering if anyone would like to help me out a little bit with doing or designing this? Cheers Sarah

i have noticed that the magnitude of the gravitational field vector, [math]\G[/math], is equal to g at that point. does that mean that magnitudes of [math]\B[/math] and [math]\E[/math] are equal to the acceleration due to magnetism and electric fields, respectively, at a point?

Suppose we have a system, devoid of any external forces acting on it, consisting of a cylindrical flywheel (mass 10 kg = mf, diameter 1 m) and an object located on the rim (mass 1 kg = mo), and rotating about a central axis at 100 rad/s = w. Thus, the object would have an orbital velocity of 50 m/s = v. The moment of inertia for the flywheel would be 1.25 kgm^2 = Jf, and for the object 0.25 kgm^2 = Jo. The total mechanical energy of the system consists of the rotational energies of both the flywheel and the object. Etot = 0.5*(Jf + Jo)*w^2 = 7500 J. Now, once the link between the object and flywheel is discontinued, the object will continue moving along the tangen…

hey, if anyone is willing, could they please give me a bit of help with this problem, i just can't quite figure it out! Thanks -Sarah

Water waves are a compression and expansion of water. So… water waves travel in water. And… Sound waves travel in air. What medium do Radio waves travel in?

here i another 2 questions, how'd i go for these ones?

If a particle is fired up with a velocity ''u'' then ''t'' seconds later a second particle is fired up with the same initial velocity and from the same place, prove that the particles will meet after: (0.5t+ u/g) Where g is gravity. The equations used are just the basic equations of motion, i have gotten an answer similiar but i cant see how to prove this exactly.

Check out this guy's Alternative physics. . I especially liked The Earth Is Motionless Center of The Universe

here are a quick to questions, how'd i do?

hey could i have some hints/help with this? .... in the next 40 mins would be great (nah sorry guys i'm being unreasonable...)

If you were going to teach someone about physics involving rotating frames of reference, where would you begin? In other words where is the best place to begin? I was thinking about starting off with the definition of angular momentum, and going from there. L=R X P From there you could go on to cover torque, and moments of inertia. The problem is I'm not sure the best place to start. The moment of inertia tensor is not for a beginner, so I need someplace else. Any thoughts? PS: My goal is to understand gyroscopes in particular, with a view towards quaternion algebra, and how it is used to avoid gimbal lock. Also, I want to tie the work here, to …