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  1. K

    Geometry textbook

    I'm from the UK so I'm actually doing my degree in Mathematics (we usually just do one subject, rather than the major/minor 'mixed course' US system). What you mention above sounds like the sort of thing I'm after. I want to review what I already know, but with an emphasis on proof. Thanks :)
  2. K

    Geometry textbook

    Thanks for the help! I need to be a bit clearer. The level that I am at is that I am just starting university, and probably the most advanced stuff I've done is calculus using hyp/inv trig functions, induction, Mclauren series etc. Hopefully that gives an idea of where I am at. What I am...
  3. K

    Geometry textbook

    Hi I'm starting university in September and wanted to consolidate my current knowledge. I got hold of a nice textbook called 'foundation mathematics' which covers algebra to fairly basic calculus, but was looking for a good one on geometry. Can anyone recommend any decent books (or...
  4. K

    Work against gravity confusion

    Say there is an object on which a force of T acts for a displacement s and there us a constant frictional force of F. Would you say that the force T does Ts J of work or that the force T does Ts J of work and Fs J of work against friction? Or is it something else? Any explanation would be...
  5. K

    Work against gravity confusion

    Ok so is this just a case of a poorly worded question, as it does not mention that the object is moving at constant velocity? (the answer in the book is mgh) Would the actual answer be that the tension does at least mgh J of work?
  6. K

    Work against gravity confusion

    Hi I've just started learning work, energy etc and the first question in the book is in the form: An object of mass m is lifted by a tension through a displacement of h. Find the work done on the object. I know that the answer is simply mgh J, there is something that I don't quite get...
  7. K

    Show that the forces form a couple (algebraic)

    Homework Statement A Triangle ABC has sides of length a, b and c labelled according to the usual convention. Forces of magnitude ka, kb and kc act along BC, CA and AB respectively, with the direction given by the order of the letters. By considering the vector sum of the forces, or otherwise...
  8. K

    Does friction oppose force or motion?

    What do you mean by a "non-inertial reference frame" and what is the force opposing friction in the above case?
  9. K

    Does friction oppose force or motion?

    Ok thats really helpful thanks. So it is the case that when an object is in motion, friction will always be at a maximum? I.e. it responds to motion, not force?
  10. K

    Does friction oppose force or motion?

    I am talking about when friction is not limiting so the object decellerates (I've tested it)
  11. K

    Does friction oppose force or motion?

    What I am asking is that once the object is pushed (assuming that limiting friction is greater that the force of gravity) if the friction opposes force shouldn't it be equal to gravity, keeping the object at constant velocity rather than greater than gravity, causing it to deccelerate? In...
  12. K

    Does friction oppose force or motion?

    I have always treated friction as 'opposing' force rather than motion, either at its limit or to maintain equilibrium. I have just realised, however, that if an object is at rest on an inclined plane, but is not at limiting equilibrium and you give it a nudge it will accelerate while you apply...
  13. K

    Friction question, maximum incline

    Homework Statement An object of mass 50kg rests on a rough plane incline at an angle alpha to the horizontal. It is supported in this position by a light string parallel to the plane. The string has a breaking strain of 200N and the coefficient of friction between the object and the plane is...
  14. K

    Moments/torque in relation to laws of motion

    I've just started learning about torque, and understand that tau=Fd, but wondered how this relates to F=ma. For example if there is a rod with a pivot in the middle (say a nail), when one end is pushed down, why does the other end move up? Where is the force that causes the end to move up...
  15. K

    Newtons 3rd law - how can this rope move?

    Of course not, I just wondered if there was something in Newtons model that said that, or if it is so obvious that we can just take it for granted.
  16. K

    Newtons 3rd law - how can this rope move?

    So a constraint force is a force that is determined entirely by the necessity for a situation to satisfy F=ma, as opposed to a force due to gravity which is determined just by the masses of objects and their positions? Also, is there anything in beginning mechanics that tells us that tells...
  17. K

    Newtons 3rd law - how can this rope move?

    Yeah I agree. I think what has confused me about Newton 3 is that when an object 'acts' on another, the magnitude of the force that it exerts is determined by a sort of mathematical necessity that occurs due the the boundries that Newtons laws have put in place. The intuative trail of thought...
  18. K

    Newtons 3rd law - how can this rope move?

    Thanks for explaining - that really helps :) I have another slightly similar situation that I can't get my head round: If an object A rests on a table B, the forces on A are its weight and a contact force from B, which is equal to its weight. By Newton 3, A must also exert a force with the...
  19. K

    Newtons 3rd law - how can this rope move?

    Hi I'm having trouble understanding this situation. Appologies if I posted in the wrong place, this is pretty simple but it's not really a homework question. A horse is attached to a large stone by means of a rope (modelled as light and inextensible). Let the mass of the horse be m and the...
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