studiot

No integration is necessary. Perhaps this definition will help as a hint

The mechanism to direct trains along the correct track is called 'points' Here is Wiki and some you tube etc https://www.google.co.uk/search?q=how+do+railway+points+work&ie=utf-8&oe=utf-8&client=firefox-b-ab&gfe_rd=cr&ei=ZrkcWb6JLc2stgfNzYXAAw

So tell us your thoughts about the subject. It is more than difficult to have a discussion with a video. So more text and less video please.

It would be nice if someone could give us a quick summary of which of Poincare's works is referred to here as Poincare's Relativity. Is it this paper? H Poincare : Recueil de travaux offert par les auters a H A Lorenz : Serie2. Tome5 Arch Neerl 1900 p252 English paper title Lorenz's Theory and Principle of Reaction.

No sweat, "I don't think that the Child's equation was mentioned etc......." So I posted some references.

I don't think that Childs Law or Equation was explicitly mentioned in the book I referenced. https://en.wikipedia.org/wiki/Space_charge http://simion.com/definition/childs_law.html https://www.britannica.com/science/Langmuir-Child-equation

What I am not sure about is are you asking our opinion because you have seen this elsewhere (as have several members here) or are you trying to sell it to us? Taking the best interpretation means I see no call for negative points. So I am adding +1 to what seems to be your latest attempt to discussion the subject reasonably and comply with the rules. However the explanations offered are weak and incomplete. Here is another omission. The metal wheel is a conductor moving in a magnetic field, cutting lines of flux. This motion will generate Faraday eddy currents which will dissipate energy. So the wheel will stop in time from this cause alone. As a matter of interest many machines, especially rotating ones, become a bit magnetised after working for a period of time.

Let me try to clear up some questions. The tunnel is straight. It does not follow the curve of the Earth - it is not at constant depth. It is not intended to pass through the centre of the Earth. If you google the acceleration at depth d you will find the derivation of your choice of this formula eg http://gradestack.com/CBSE-Class-11th-Science/Gravitation/Acceleration-due-to/17543-3563-24279-study-wtw or John Cuthber's correct but OTT link. This is not about the shell theorem all you need is the formula. Now I have amended the usually presented formula ( as in my link) to make things easier. This is simply to replace the depth, d with the distance to the centre, a Obviously a + d = R or a = (R - d) This clearly shows the relationship between g at the surface with g' at any point p inside the Earth. g' acts along the same line SPC as g The shell theorem simply states at any depth d or distance from the centre a, we can remove the shaded annulus and consider gravity as though it were a new sphere of radius a. Hope this helps

17 views, no replies. You will find that folks are more inclined to take the time to help if you take the time to make your original question intelligeable. Any of the actions you mention might increase the reaction rate, but it depends what the reaction is. Do you know what the conditions for each of the actions you mention increasing or decreasing the rate might be? To answer any of these you need to properly (fully) specify the reaction, which would include the conditions. I have now put more effort into beginning an answer than you have into the OP.

I feared interest in this delightful problem had died so thank you. All the necessary information is in the OP and in post#14 I gave function the formula he requested, which is easily goolgable or derivable as John Cuthber said. You will also need this. Is the length of the tunnel or its depth relevant?

One last time (pun intended) There is no such thing as absolute time, which your statement necessitates to be true.

I make k = 0/0427, pretty close to your figure. I make the rate equation Rate = k[H2] ie independent of [P] from the supplied data. I have to admit that I know little about the reactions between Phosphorus and Hydrogen but I would guess that the reason this appears to be a first order reaction is that it is a multistep reaction with the initial dissociation of H2 molecules as the rate determining step.

Surely we should look for common or garden reasons for any observation, before seeking Men in Black at the bottom of the garden. What was wrong with my engineering commonsense comment? The next step would be for someone to devise experiments to eliminate my explanation from enquires. Enter Mr Plod?

You know, I think the cloud is really good. After all when your pc is unbootable/uncontrollable either because of a hard drive crash or malware, all you have to do is get your stuff back from the cloud. Just one small hitch, you need a working pc to effect this. A backup strategy on its own is useless, you also need a recovery strategy. My backup and recovery strategy. 1) Windows and programs live on a system drive. 2) Data is housed on separate data drive or drives. The sytem drive is imaged using REDO when and can be restored either to the old drive after cleaning or a brand new drive. REDO handles all the partition management stuff and runs directly from its own boot medium (CD for me but it could be a flashdrive etc) The DATA is copied to a NAS system and perhaps elsewhere as well. In the event of uncontrollable malware I simply wipe the system and data drives and restore to before the event.

The edge of the universe? This reminds me of a story about Columbus being told he would fall off the edge of the World.

This maths starts with an elementary mistake. The forces are not balanced yet the author writes an equilibrium equation as though the ball and wheel were in equilibrium. They cannot be in equilibrium since they are in motion, suffering accelerations and decelerations. So can we have a correct analysis please?

A video from 1823?

Not quite I think. Check the geometry very carfully for the position of the centre of gravity.

Maybe it is your English, but you made a statement about Newtonian mechanics that was only partly true. Perhaps you should try to improve your English, then your Newtonian Mechanics before doing any more relativity? I thjought you might like to try the Newtonian puzzle I posted in the puzzles section (about Alice) The result is quite suprising.

Force = time rate of change of momentum. But Newton's first Law also considers the situation where there is motion, but no force. Where there is motion, but no force, there is still momentum. There is just no change of momentum.

Be aware that the previous Ransomwares later versions (cryptolocker type) could access cloud remotely stored data, on your server or the cloud. This would be locked as well.

Or sometimes not, as dictated by Newton's First Law.

And I'm sure that same motor will be much more difficult to start after standing still for 5 years in adverse weather conditions, poor starting due to seizing of bearings etc. Motors run in journals, lubricated or self lubricated. These are designed to be self optimising under running conditions, but gravity etc will redistribute the lubricant I see no difficulty with a short period after stopping where the bearing remains close to the optimum.

The way to teat momentum, velocity, etc relativistically is to use the 4D versions That is use 4-momentum, 4-velocity and so on. These physical quantities are much better behaved, just as you would be with two arms and two legs, rather than one chopped off. If you must use 3-velocity then you have been told several times now that there are no two velocities v and v' that add to c. The process of addition (or subtraction) is not one of simple adding two plain numbers together.

As always, Wiki is not quite up to high school maths The value of gravity at distance a = (R - d) from the centre is [math]g' = g\frac{a}{R}[/math] Where R is the radius of the Earth, a is the distance from the centre, g is the usual surface acceleration and d is the depth. edited to improve formula.