Recent content by colin9876

I find it the most intriguing paradox- many sites give poor and differing explanations. For the record, the point about the upper budget is not relevant - I could have said a genie with infinite resources filled the envelope. (i) So either its better to swap ... or it makes no difference...

envelope paradox?? Maths can sometimes be nearly as interesting as physics... There are two envelopes on a table. Both have cash in, you don't know how much but one has twice as much as the other You can pick just one envelope, and you are allowed at most one swap. You choose envelope A say...

the kinetic .5mv*v goes into Potential mgh v*v=2gh v=sqrt(20h) so in ur example where h=1 then v is about 4.5m/s if you lost 10kgs and had the same jump force you would go 91/81 higher, approx 1.1m

This baffles me, because the device outlined below could create energy ... Theres two tanks A & B with a microscopic gate between them Air in A & B starts at say 25 degrees whenever a faster than average moving molecule approaches the gate in A a sensor opens the gate and let's in pass...

It takes energy but where does the energy for this dissociation come from. Im wondering if it comes from the heat withing the liquid - if so possibly removing the ions would allow more to remain dissociated and possibly lower the temp of the liquid

Excuse me ? No one asked to contribute to my question, so that sort of attidude not required thanks. The post you reference does not answer the point about 'sorting out' the fasted moving molecules. My question is if there was some way to sort molecules could you get some hotter water out of...

so if gravity travels much faster than light would it be possible in theory to transmit data through an artificially pulsed gravity wave, faster than the speed of light?

free energy?? water disasotiates to H+ and 0H- if you could take the dissasociated ions away, and combine them how much energy could you get out? In the liquid remaining, more would dissosciate, and the process could be continued. Where does this energy come from - it sounds like free...

Can someone explain if my understanding is correct- that temperature of say a liquid is proportional to the speed of the molecules? My idea is if there was a way to sort different molecules by speed, could you say in theory, take 1litre of water at 30degrees and pick out the fastest molecules...

Thanks! I did have a go from first principles integrating from 0 to pi, rings of width d(theta) but it got complex so the Wikipedia post was very helpful. In a way its quite amazing all the different forces on a sphere add up so niceley to be the same as a single point!

ok i get the idea of integrating hollow sphere caps from 0 to r but its it seems very difficult to calculate what force each spear cap will produce as the mass points are ar different lengths from the satelite, and the force lines are at different angles? If I could calc what a hollow sphere...

can u explain a bit more please because vague comments are not much help!

ok, symmetry - so I could simplify it to be say half a sphere, or quater of a sphere but its still impossible to integrate?

Homework Statement planet with mass m and uniform density and radius r, show by integration that the force this body generates on say a satelite is equivalent to a point mass m at the center of the planet Homework Equations i know that gravitational pull is inversley to r*r The...

why do the shells of atoms contain at max 2,8,8 electrons etc? seems a strange pattern it would seem more logical to be something like 2,8,18 ... or something that increased as n squared or even n cubed??