studiot

Sadly, one usually leads to the other. I agree most don't stop to consider the difference unless asked but then (my experience, straw poll only) But many middle managers in many walks of life ape the utterances of the high and mighty to justify their own inappropriate policies or responses to inappropriate directives from top management. We need better examples from the top down. I couldn't agree more. +1 Water is a prime example. We all to often see pictures of flooding on our UK screens, followed by bleats from the water industry that we are 'running out of water'.

Wow, yes, simply put but irrefutable. +1

Quantum mechanics did not appear in my (advanced Nuffield syllabus) A level Physics. But it certainly took an extensive role in my A level Chemistry in the 1960s. And Mrs T would have undoubtedly studied QM via the famous text (Physical Chemistry) of that time by Professor Moelwyn-Hughes, amongst others. Of course Chemists and Physicist have very different uses for QM and therefore different views on the subject. I could equally well make a case that Mathematics is the primary discipline, based on the famous texts by mathematics Professors Coulson (Valence) or Mott and Sneddon (Wave Mechanics and its applications).

I stand by what I have said. The use of δx may have started with Leibnitz, but it has been used extensively in many other roles since. This often clouds his view of δy/δx as a limit as two infinitesimals simultaneously tend to zero.

Sorry I didn't realise you had just joined. The 5 post limit is only in the first 24 hours. This cuts down on spammers. After that you have (preferably sensible) unlimited posts. However I think there is a problem with your description of the question. If this is true there is no solution. Look carefully at my sketch. If the horizontal distance, x, is always 40.135cm then it is constant. The line x = a constant is vertical and parallel to the y axis. So as the inclination, θ, increases, the slope distance (hypotenuse) increases until it is infinite when θ = 90. ARE YOU QUITE SURE YOU DO NOT MEAN THAT THE HYPOTENUSE DISTANCE IS CONSTANT ? I await your answer tomorrow with interest. This one is only for constant velocity and the velocity is not constant here (That is how you get acceleration) You do indeed need this one, but the first two terms on the right are zero. And you will need to differentiate it to get a minimum. But it is not a difficult process. But again, please don't use 'x' You may want to measure in a different direction and x is not general it refers to the horizontal. The general symbols for 'distance' is usually taken as 's', whcih can be measure up, down, sideways, along a straight or curve or jagged path or whatever.

I'm still here What kinematic equations do you know connecting distance, time and acceleration? I'm still here What kinematic equations do you know connecting distance, time and acceleration?

I assume the angle of inclination of the plane is measured from the horizontal. That would be usual. Please don't use x for vertical distance it confuse people, me in particular. Let us say that y is the vertical distance. And the horizontal distance is x. The hypotenuse is not needed. Then the tangent (not the cosine) is needed tan θ = vertical distance/horizontal distance = y/x Since x is given yes we now need a kinematic equation, do you know any?

Yes that is true. But it does not answer my question Are you using a translator? Have you drawn a plot with the two points and drawn in the (straight) line between them? If we call the points 1 and 2 with coordinates (x1 , y1) and (x2, y2) What is (y2 - y1) ? What is (x2 - x1) ?

Do you not think they have confused many voters with their misuse of these terms?

Got it all into the title. When will politicians learn the difference between spending and investment ?

I'm sure the question does not say exactly that. So post the whole question and anything you have done with it. Have you done any trigonometry? Or can you tell me the difference in x coordinates and y coordinates between the points?

I have no idea of your mathematical background, but the link I gave has video and maths solutions galore. So enjoy and come back if you still have problems. here is a start Let θ be the angle of inclination of the plane. Then the vertical distance the block falls = ??? (for you to fill in) Now we pick an equation from kinematics that relates to time and acceleration and equate this to the vertical distance

mimimycin you have 5 posts in total in the first 24 hours here and I don't know if you can post attachments in that time. So you have 1 post left today. The best thing would be to say if you know what equation sensei was talking about and post what you have done with it.

This is known as the brachistochrone problem. Here is lots about it. https://www.google.co.uk/search?source=hp&ei=r6yXXdrKJMTekgXX6rPwBQ&q=brachistochrone+problem&oq=brachistochrone&gs_l=psy-ab.1.1.0i131j0l9.1452.7864..9268...0.0..1.1912.11618.2j4-1j3j2j5j1......0....1..gws-wiz.......0i10.xgMG83jFjVw This question is often used to indtroduce the calculus of variations and Euler-Lagrangian mechanics.

If you explain what you have done with the information that sensei gave you , perhaps he will add more.

http://faculty.uml.edu/james_hall/84124/20pt1.htm

Is this homework?

We also produce cheese in Somerset, though we don't have much chalk. Hinkley has yet to be completed, perhaps it never will. The other similar power stations this company are building are 15 years behind schedule and something like 100% over budget. Tidal generation could produce far more electricity far more cheaply.

Excellent point I should have mentioned. +1 The atoms in the Sun are in the 'fourth state of matter' - the plasma state.

Whatever this clearly demonstrates the folly of spending £30 billion on Hinckley C.

Anyone who has driven a motor car will know that the insect imapacts build up on the front windscreen and grille, not on the side or back windows. The first picuture in your second post looks fabricated to me. Tell us about its progeny please. In fact providing details of all of them would be better.

Hi Moon , have you been reading Stephen Coonts again? https://www.google.co.uk/search?source=hp&ei=KiSWXY6sBsT3kwWe5YjgBw&q=stephen+counts+saucer&oq=stephen+counts+saucer&gs_l=psy-ab.3..0i13l3j0i13i30l3.1016.10036..11042...0.0..0.1034.6056.5j5j4j3j1j1j1j1......0....1..gws-wiz.......0i131j0j0i3j0i22i30j0i22i10i30j33i160j33i21.NM1pFHYAfQg&ved=0ahUKEwiO6c3Kw4DlAhXE-6QKHZ4yAnwQ4dUDCAc&uact=5

Is this not a duplicate thread?

The classic example is the ice skater, spinning on the ice. She speeds up or slows down her spin by drawing in or extending her limb(s). Try this thought experiment. Reach down give the rod a sharp twist with two fingers, like if you were spinning a coin on a table top. Then let go.

So is the original arrangement being abandoned as unworkable? The point about a couple is that you can apply one to the rod to get the rotation started, but there is no guarantee it will continue for very long. As a matter of interest, if you have a large m1 and a small m2 you have a situation that occurs in nature. There are quite a few molecules that have a heavy atom at one end of the bond and a very light one at the other. They perform a very peculiar sort of tumbling rotation. I believe there are macro toys based on this as well. Final comment. When you have rotations about 3 axes (known as Euler axes) , two rotations are stable but the middle one is wildly unstable. This can be demonstrated by trying to spin a matchbox/book/brick about each of the three axes and observing the behaviour.