# Search results

1. ### B Is non-linear Tension Force possible?

I seem to remember from my school days that Tension Force can only be linear. Is this true? In 1 (in the graphic) the tension will follow the line of the rope In 2 there is an unbendable, unbreakable, steel cable formed into an arch. a ] In 3 which direction will the Tension be? b ] In 3 if...
2. ### I Horizontal Tension Force equation

You’re probably right about the rose. But let’s say each petal opens from the centre with a force of 123kn (very strong roses). There are two petals each pulling with the same force. The cotton is not massless (as infinite acceleration hurts my brain), so let’s say it has a weight which is so...
3. ### I Horizontal Tension Force equation

(not a homework question - I left education over 45 years ago) Hi, this just out of interest as I have been googleing this and can't find the answer I know the equation for tension force, for example a weight on a string, block on a ramp, etc. But is there something similar for a horizontal...
4. ### I Maths required for rotation point

Hi The first thing to say about this is that I don’t have a clue where to start. What I’m looking for is somewhere (maybe a website or just a brief introduction) I can study – and learn – about the forces involved and the maths required. _______ Say I have an item/length/beam/weight/etc (C...
5. ### B Rotating line - x axis point

Hi (I hope this is the right place to post this - sorry if it's not) Say I have a line (in the graphic is shown a 10mm but it could be any length) and it rotates around a point at one end. What is the formula to get the length along the x axis directly under the other end of the line. In the...
6. ### I Turning radius of curved plane on an inclined plane

I'm sorry but that's not correct. I am trying to introduce something like tan = v 2 / g r (banked turn) - of course I have left out F (friction) but if I can include this it go a long way towards what I'm looking for
7. ### I Turning radius of curved plane on an inclined plane

Yes I have. This is just one of the many sites I've seen that seem to me to have got it wrong. On that site there is a section called "Force Balance For Skier Going Around A Purely Carved Turn" But that is looking at this as an inclinded plane whereas it's more in line with (for example) a car...
8. ### I Turning radius of curved plane on an inclined plane

Hi again. I hope this is the right section to ask this question. Not home work (I'm retired) but yet another mind game I'm playing (and still getting nowhere). I have trying to work out the formula for how a ski will perform a carved turn. I have looked at many (many Many) websites and they...
9. ### The physics behind the Dew Point phase shift

I know that at a certain saturation vapour pressure the gas will shift to liquid. What I'm trying to work out is why? There must be something going on with the molecules - I think it may be down to their speed (maybe they slow down and at a certain speed they can't rebound so much - but that...
10. ### The physics behind the Dew Point phase shift

Many websites gives the results of Dew Point but not the reason. What is going on at the dew point? Not the result (at a certain VSP vapour becomes liquid if it can find nuclei to coat) but the reason for the result. I have been reading up on this – just out of curiosity – and would like...
11. ### The first law of thermodynamics and the dry adiabatic lapse rate

Thank you. You have explained it wonderfully.
12. ### The first law of thermodynamics and the dry adiabatic lapse rate

Hi Thanks for the answer. I am trying to understand exactly what is going on. If no heat/energy is lost to the environment, then (I can't think of another way to put this) where has it gone? I assume the net temp (avg kinetic energy) is still the same - as no energy has been lost. So is it...
13. ### The first law of thermodynamics and the dry adiabatic lapse rate

Say there is a parcel of air rising and cooling, what is going? Is it that the net kinetic energy (Temperature) of the parcel is distributed over the (new and larger) area/volume? Or Is it that the parcel is undertaking work as it presses outwards and so looses a corresponding amount of kinetic...
14. ### Why is white paper white and not black

Right let’s see if I have this. Light is always additive. When all the colours are added you get white Non light source objects (with a very few exception) are always subtractive. When all the colours are subtracted you get black. So if I shine a light onto a white object all the...

16. ### Why is white paper white and not black

I think I have it. The paper is white as all the light is reflecting equally, so the colour I view is in reality additive - being that I am seeing light. If I add red ink this will “subtract” some wavelengths and the light I see will be red - so the cause is subtractive but the effect is...
17. ### Why is white paper white and not black

So the light is reflecting from the paper and as all the wavelength are reflected equally and it looks white?? But if this is the case and I were to add to red ink to the paper this would absorb more wavelengths outside of (very approx) 680nm to 720nm so this would be a subtraction from the...
18. ### Why is white paper white and not black

I'll put it another way. If direct source wavelengths between (very approx. 400nm – 750nm) are reflected with some omissions, why is the result produced as an additive, “plus” the omissions and not as a subtractive series. Or – why does a non complete series of direct source wavelengths...
19. ### What is time?

Have a look here http://en.wikipedia.org/wiki/Time
20. ### Why is white paper white and not black

Why is white paper "white" and not black I understand this may seem a silly question but I really would like to know. As far as I understand it (may be wrong) additive colours (visible wavelengths) when combined equally produce white. Subtractive colours, when all the colours are equally...
21. ### Do photons oscillate?

Hi Drakkith Thank you that makes sense. I will do some more reading and than come back with some more silly questions :redface: Thank you for helping (it's really quite fun all this) Karen
22. ### Do photons oscillate?

OK thanks. I have not been in a class room for over 35 years and am simply trying to understand things as a hobby. So I really do appreciate and answer you have time to give. Back to my thoughts. Looking your answer it seems you are saying that at a quantum level there is no oscillations...
23. ### Do photons oscillate?

I was always taught that light moves in transvers waves - is this not correct. - and that the wave consisted of photons (packets of energy). Are you saying that em is just energising one photon twhich then passes this onto the next and so on (like an electric current down a cable). If this...
24. ### Do photons oscillate?

OK I understand it’s a silly question but I have been thinking about this all day. Say you have an EM wave moving out from its source in a transverse wave formation. Where does the oscillation come from? And (another silly question) is the oscillation affected by mass? In my simplistic...
25. ### UV light absorption by transparent sheets – how?

I have found this on wiki but (as you can see) it does not go down far enough. http://en.wikipedia.org/wiki/File:Polycarbonate_IR_transmission.png Does anyone have a link to a (peer reviewed) paper with the same info but going down into the UV area I say peer reviewed to keep away from the...
26. ### UV light absorption by transparent sheets – how?

Thanks for that. I need to do some more reading :redface:
27. ### UV light absorption by transparent sheets – how?

Ah, I think I have it now. I have found this page http://www.chemguide.co.uk/analysis/uvvisible/theory.html Seems to answer my question Thanks
28. ### UV light absorption by transparent sheets – how?

Well I “assume” that there is a similar process taking place for most reasonably similar wavelengths. May be totally wrong about that. Say you have a blue ball. It has absorbed all wavelengths other than (for example) 470nm as there are no electron frequencies of 6.3786e+14 (well that’s what...
29. ### UV light absorption by transparent sheets – how?

Ok thanks for the responses to my other question; I think I now have it. I have a follow up question – that is almost on the same topic (but not quite) The complete spectrum (arund 200nm to 380nm) of UV light is absorbed by some plastics?? Elections will be moved to a more energetic orbital...
30. ### H2O Vibrational Transitions (molecular as opposed to election) Why ?

Than you all for your time and knowledge. I "think" I have it now. Due to "vibration" of the H2O being at the same frequency of some of the spectrum (many the shorter wavelengths - greens, yellows, reds) it is those that are absorebed. But I stil don't understand why this would not be the...