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    Newton's Laws Of Motion

    I cant do anythng abt that, thats our exam rules here, its tough competition. And ya, ofcourse, some others out of that 75 are simpler. But if one can do this problem in the least possible time,(i dont mean 1 minute for this problem), then he can save time for the other problems. And it is not...
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    Newton's Laws Of Motion

    The problem does not state that the two blocks, B and C move together (i.e. that they have the same acceleration). It was just a hint given at the back of the book. So, u say that there is no direct method to identify which blocks will move together, or whether they all wud move with different...
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    What am I missing?

    Then i dont think it'll ever come to 15. maybe the answer in the book is wrong or there is a misprint in the question. I didnt notice that it was the weight of the box that is 200. I thought it was the mass. if u take it to have a mass of 200 kg and not weight, then the answer is 15m. Other...
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    What am I missing?

    Ya, obviously the answer will be 15m. And where did the g go? its 4000 J, not 400. Now 76% of the total work done by you will be 4000. Now, solve that. In PF, u'll have to do some work by yourself, no one will post full solutions (PF rules).
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    What am I missing?

    I just get the feeling that the 2 m is the vertical height above the ground to which the box is lifted. So, you can surely find the potential energy of the box at a height of 2m, right? Where does that P.E. come from? Now 24% work is wasted. leave that. So, the rest 76% of your work is spent in...
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    Newton's Laws Of Motion

    Oh, ok. I got it. But what about the blocks B and C moving together? why will they move together? I mean why will B and C have the same acceleration? but i all the frictional forces will not act towards left. the frictional force on B due to A and on top of C due to B, will be directed towards...
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    Newton's Laws Of Motion

    INTRODUCTION: The following is a problem of "Newton's Laws Of Motion". It is a typical problem of this chapter. I am having problems with some parts. THE PROBLEM IN BLACK AND WHITE: "Find the acceleration a_{A}, a_{B} and a_{C} of the three blocks shown in the diagram (not included here)...
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    Relative Velocity concept help

    WHY 0 m/s? why have u added 0m/s north in each of earth's ref. frame and rain's ref. frame?
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    Relative Velocity concept help

    Thanks, I feel i am starting to understand, but could u please tell me why it is v_{rel} = v_{man} - v_{rain} and not v_{rel} = v_{man} + v_{rain} or why not v_{rel} = v_{rain} - v_{man} ? Thanks a lot (Thats all i can give u).But of course i will always remember you as the "GREAT MAN WHO...
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    Relative Velocity concept help

    i dont think one can do all rel. vel. problems with that... Thanks a lot. But now, what if the rain is not vertical, that is no component is zero. Lets say: "To a man moving due north with a speed 5m/s, the rain appears to fall vertically. When the man doubles his speed, the rain appears to...
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    Relative Velocity concept help

    I guess this is going to be my worst thread. I'm so sick of this stupid concept "relative velocity" that i'm in no mood to present this thread in my "exemplary style" for which i have been included in the "best homework threads" section. I'm sorry for that, but its true. I have no problems...
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    A few problems on MOTION IN ONE DIMENSION

    Thanks... THANK YOU: Hey, thanks a lot for helping. Now I got the second one. But are you sure the book's answer for the first one is wrong? I am quite sure it is wrong. But was just being surer. Anyway, thanks again.
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    A few problems on MOTION IN ONE DIMENSION

    I Dont Get The Second Answer. I think the first one is ok, i.e. maybe the answer given in the book is wrong. But i dont get your second answer. and its 155 km/h and not m/s. its a jeep, not a supersonic jet. only the velocity of bullet is 180m/s.
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    A few problems on MOTION IN ONE DIMENSION

    A few problems on "MOTION IN ONE DIMENSION" INTRODUCTION: Here are a problem on "Motion in one-dimension". THE PROBLEMS: (1) "Car A is just behind Car B.Both are 5m long.The velocity of A is 15 m/s while that of B is 10 m/s. Find the road distnace covered by Car A to cross Car B." WHAT MY...
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    A few problems on Optics

    But lets say we consider a point object and neglect the increase in size. But now if we look at that point object from a place above water and in between the edge and the vertical line through the object, then where will the object be? I know its confusing but thats the best way i can explain in...
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    A few problems on Optics

    That Is Exactly What The Question Says... Thats exactly what the question says , word for word. I have already given the whole question. But maybe there is a misprint in the book. Anyway, can u please tell me what change would occur if the observer O is not near the edge but looking from a...
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    A few problems on Optics

    I do know about bending of light rays at surfaces, and when and how or how much, etc. if we look from a medium which is denser than water, then obviously the opposite of what happens here will take place.That is the image will be formed below T. But the thing is that my book says that option...
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    A few problems on Optics

    I wanna know something else... WHAT I KNOW: I know that water is optically denser than air. So, obviously the rays from T will bend away from the normal (perpendicular) at the water-air interface. That is not my question. WHAT I WANT TO KNOW: I cannot understand the meaning of options (iii)...
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    A few problems on Optics

    INTRODUCTION: I am having problems solving Some Optics MCQs recently. THE PROBLEMS : (1) T is a point at the bottom of a tank filled with water, as shown in the diagram. The refractive index of water is 4/3.YPT is the vertical line through T.To an observer at the position O, T will appear to...
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    A Few Problems: MAGNETISM AND OPTICS

    I THINK SO: Ya, i think that is the case. And i have understood the problem now.It is a sphere of radius R and not a lens. WHAT I HAVE UNDERSTOOD: We consider refraction at the first surface.Now if an object outside the sphere has to form an image at the same distance from the sphere, then the...
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    A Few Problems: MAGNETISM AND OPTICS

    A Bit Confused... A BIT CONFUSED: ***But i'm still a bit confused about how to do the part (a) of question (2). How do i get the distance at which the object should be? The second part about the air bubble is now clear. But i'll be grateful if you could kindly explain 2(a) more clearly. ***And...
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    A Few Problems: MAGNETISM AND OPTICS

    INTRODUCTION: Hi, here i am stuck with a few problems. One from Magnetism and the rest from Optics. THE PROBLEMS: (1) A wire PQ of mass m can slide frictionlessly on two conducting rails spaced a distance l. A current i flows on into the wire PQ with the help of a current generator.There is a...
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    More conceptual MCQs

    2> It is that the pressure at a point inside a liquid is given by hdg, where h is the height of the water column above it, d is the density of liquid and g is acceleration due to gravity.Now as the bubble was much below the surface of water, the pressure on it was much more(h is more), so it was...
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    Help for a few questions

    Hey, i totally disagree with you. In this case the capacitor is not connected to a battery,is it? No. then how can the energy decrease when we move the plates of a capacitor?where will the work done by you to move the plates go?Let me tell u. if u are thinking that the energy stored is 1/2CV^2...
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    Help for a few questions

    3> ya the waves will also have to have a constant phase 4>when the plates of a capacitor are moved apart, then the energy stored increase. see,if u move the plates apart, u have to do some work against the attractive force between the capacitors. where will this work done go? this will be...
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    Heating Effect Of Current

    so in this case, what would happen if the battery is shorted. plesae explain. it is the first time i'm coming across short circuit problems. thanks.
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    Electric field due to || CONDUCTING plates

    INTRODUCTION:Neither do i understand u, nor ur book.please try to b more specific next time.make headings and under each explain ur problem part by part. it becomes easier. wht is s? wht is s1? nothing is clear.But anyway as far as i can understand i am explaining. CONCEPT BOOSTER:Since the...
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    Heating Effect Of Current

    INTRODUCTION:Here is a problem on "Heating Effect Of Current".I can't understand a part of it. EXACT PROBLEM: "A battery of emf E and internal resistance r is supplying current to an external resistance R.(a)Show that the power dissipated in R will be maximum when R=r.(b)What is the maximum...
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    Magnetic Field due to a current

    Thanks... THANKS: Thanks a lot, i got it now.I didn't remember to take the limits.:smile: :smile: :smile:
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