studiot

The numbers might be different for pneumatic tyres, but the principles remain the same. The physicist that I had a most enlightening discussion about this with is also an advanced/skid driving instructor. You can treat this as a learning opportunitity or you can be a smart___ and remain no wiser.

Robittybob, I note you have spent several pages considering what happens in two directions. This, more advanced question has puzzled many and can be approached not from the direction you have taken but from the other direction. Start with a body moving in a straight line against friction and then consider what happens as it enters a slight bend and a radial force appears. This is a simpler approach. You might like to use all that others here have you to consider this question that appeared elsewhere.

I had always thought that the axiom set had to be mutually consistent. To take an extreme example there is nothing to stop me stating two axioms 5=7 and 7=11 and then stating, as you have done Incidentally what do you understand by the axioms in mathematics in relation to addition and subtraction? How many are there? Please state these for my benefit.

Here is an extract from the GCSE syllabus. Note that word equations do not require quantities or balancing and that excess reactants are not mentioned. In fact balancing is only reuqired in the 'higher tier' Here is an extract from a chemistry helpsite with a similar question about the reaction between iron and oxygen. Note that there are different oxides of iron but you don't even need to know which one.

No it is a word equation. If definite or even equal quantities were intended then the equation would have included words to suit. The only safe conclusion you can draw is that some hydrogen + some oxygen or an indefinite amount of hydrogen reacts with an indefinite amount of oxygen. That is correct use of words.

Strange has it with that old saw Read the question, then check you have read it correctly. Whilst it is indeed common practice to omit chemicals that take no part in a reaction, the question specifically asked about those that did. So any 'spare' oxygen that took no part and remained unchanged would not be recorded. It would also be the case for any 'spare' hydrogen if there was excess of that substance, which is possible. You cannot include energy without stating more detail about the initial and final conditions.

For you to be able to say that is the purpose of the homework help. Now you understand what you are doing and have a sound systematic method for future problems.

That is what I meant by A manifold is the playing field (football pitch, tennis court, running track, swimming pool, video game screen etc). Each of these are housed within a stadium of some sort. The rules of travel between points on the pitch may may the shortest distance between two points 'curved' compared to the stadium. So a runner, confined to the track has to run around the track from the start line to the finish line. This is a curved path compared to that taken by the games official who can walk across the middle. The runner's path would be considered a geodesic, however.

You need to define the manifold before you can discuss the geodesic. The concept of warped or not has no meaning in the context of the manifold only in the space in which it is embedded, or perhaps with comparison with another manifold. Difficulties can arise when attempting to mix Physics and Mathematics concepts.

OK so we need to review what parallel means. (We can do the series after since the next stage will be a series combination, in case you are pining for one.) Capacitors have two terminals. Call them A and B and the capacitors ! and 2. If we have two such with terminals devices {1A , 1B} for device 1 and {2A , 2B} for device 2 and Directly connect the A terminals together and the B terminals together The devices are connected in parallel. So 1A is connected to 2A and 1B is connected to 2B, directly. ************************************************************************************************************ Now if we reverse on of the devices so that So 1A is connected to 2B and 1B is connected to 2A, directly. The devices are said to be connected in anti-parallel. For most capacitors it does not matter which way round we connect or which we consider to be the A terminal and which we consider to be the B terminal. But for some devices it does matter and this includes some capacitors. Such devices are called polarised. (polarized in American). Other polarised devices like this include diodes. *********************************************************************************************************************************************************** So look carefully at the diagram. Can you see that in the original the 1 and 2 capacitors had their AA and BB terminals tied togerther and that is the same for the 13 and 17 caps? So replace the 13 and 17 with their parallel equivalent. Can you now see a simple series combination as a result of that substitution? Hint it should be a 30 in series with a 5.

Well I was hoping you would see that the 17 and 13 capacitors are in the same situation as the 1 and 2. Incidentally it is good to use the units, but do get the correct ones. Capacitors are measure in Farads., not Siemens, which is a unit of conductance. (Mostly we work in milli, micro and nano farads)

I assume you mean the reduced capacitance between the points A and B? Pick either point A or B (I suggest B) and rederaw the circuit on a rectangular grid, with A at the top and B at the bottom. The relationships should become apparent then. Have a go and I will post my version in about half an hour. Here is how to build it up. Can you see what comes next?

Well I'm sorry if you take umbrage at my turn of phrase but it was intended in a friendly fashion to save you a deal of work. I have absolutely no idea what you mean by the underlined part of your sentence. So expand on your thesis to explain your terms and controlling conditions. Thus far you have made quite extensive claims, without development here.

One aspect that is missing in this discussion is communucation.

First the good news to encourage you. This idea is sound, but really in the province of applied maths or physics, rather than pure maths. Now the bad news (but good at the end) This is the basis of Field Theory in Physics and has already been substantially (I hesitate to say completely) worked out. (Field theory in Mathematics is somewhat wider in ambit) In Physics a Field is a construct where you can assign a value or set of values to every point in a particular region (finite or infinite) of space/ spacetime. Much study has gone into the relationships between the values at each point. Those relationships may be linear or non-linear. So I suggest you study some of that and use your ideas to help you organise the enormous body of existing material in your own mind, before trying to reinvent the wheel. If you do come up with anything new then others will expect you to fit/add it to the existing framework.

Further applying a damp cloth to many oven pot materials (pyrex, ceramics) can lead to potentially explosive cracking.

You are working an a seriously hands on experimental area. So try it and see. You would proabably need to set up a pilot test process anyway.

Are you hoping to use this for filtering your acid fumes from your other thread?

I have just returned from my sojurn in Scotland and I am reading this on my Avastpro protected system. Avast see see no problem with SF, although I has reported issues in the past. It is, however, offering a program update (as opposed to a database update). I wonder if the issue is generated by the udated version of Avast. I have seen this on previous occasions with updates. Thank you endy for that highly informative link. +1 The good guys must stick together on this.

I suugest you look into the "Kronecker delta" and the "Levi-Cevita epsilon" symbols. The Levi Cevit is the one you want. Look here for a discussion. https://www.physics.ohio-state.edu/~ntg/263/handouts/tensor_intro.pdf

I think the wood panelling is purely for architectural purposes. The triangular objects attached to the ceiling are probably an attempt to condition the auditorium characteristics by controlling sound reflections. The issue is that reflected sound can lead to strong undesirable standing waves between opposite faces/walls of a rectangular enclosure. You cannot eliminate these completely, but the triagular pitch of the roof helps. High quality loudspeakers often contain internal panels, deliberately set at odd angles to obviate this problem with rectangular boxes.

Actually, not quite. Mg is the correct abreviation for mega grammes or grammes times 1 million. So yes 1Mg - 1000kilogrammes or 1000kg and yes this is a metric-ton, the correct term fot this is tonne, not ton. This is note quite the same as an imperial ton = 2240 pounds. Yes you seem to have a strategy that only needs slight amendment, really to look at it form a slight different angle. Whether the train is accelerating or travelling at constant speed, you can assume the friction is the same, since you are not told any different. So when the train is accelerating the loco is pulling for two reasons. 1) To apply the acceleration Force 2) To apply the pull to overcome friction. These two are additive. To give a total force F1 = Fa + Fr = the force in the drawbar under acceleration When the train is travelling at constant speed Fa is zero so F2 = 0 + Fr = the force in the drawbar at constant speed You are told what F1 is and what Fr is and asked to calculate F2 How is your stategy coming on?

Another science forum I visit has recently reported 4 thousand spam messages from the same 'person' in one go. A different one, also plagued with spam, enforces a halt state of about 30 seconds when you first login. Most bots go away in that time.

Thank you John and pavel for your support but my short post was obviously not completely clear. You don't only have a duty to think about normal and correct operation you also have a duty to think about a failure situation. When something goes wrong it is too late to start trawling the internet for help, free or paid. You need emergency plans in place and immediate access to personnel with the correct knowledge and training to deal with any situation that might forseeably arise.

OK I see the question, what I don't see is any strategy for solving it. If you can come up with one we can fill in the detail. Do you understand what the question is asking? Hint It gives you details what happens when the train is accelerating and Force = mass times acceleration. It implies that even when acceleration = 0 (Hence that force is zero), other forces must be acting if there is still a force in the coupling. Can you think what these forces might be?