Recent content by Sleve123

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    Why does the uncertainty principle imply randomness

    I'm trying to get my head round this. I don't see why our inability to measure the world around us means that at the quantum level things must be random. I understand that measuring momentum of a particle to a high degree of accuracy means losing accuracy in it known position. But I don't...
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    Average power needed to lift an object

    Your acceleration is wrong, the 'V' you worked out was the average velocity, you can work out the acceleration using s = ut +0.5at^2. Alternatively assume the lift is of constant velocity and say: mgh / time = power
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    Finding the max wavelength for two waves to interfere destructively

    Homework Statement i) Two waves travel between two points along paths that have the same length 4.7 x 10^-7 m, one travels in a medium having a refractive index of 3.5 while the other travels through a vacuum, how long does in take for each wave to travel between the points? ii) If the...
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    Will CMB ever stop being detected on Earth

    Thanks that helps a lot.
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    Will CMB ever stop being detected on Earth

    When I mean point then, I mean a sphere, ie the radiation coming from all directions. I'm getting this idea from the fact that some parts of the Universe will never be observable to us on Earth because the vast distances inbetween meaning that the space is expanding faster than the speed of...
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    Will CMB ever stop being detected on Earth

    Not that it has become so small it is undetectable; but the point from which it was emitted is such a distance away that the expansion of space between Earth and that point is greater than the speed of light (like swimming upstream in a river going faster than you can swim).
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    Studying Emissivity Effects on a Copper Box Experiment"

    Homework Statement The experiment we did was pretty basic, it was a copper box with five different metal rods (unlagged and of equal lengths and diameter) welded onto the bottom, on the bottom of each were pins stuck with petroleum jelly. Hot water was then added to the box and the order at...
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    What is the specific gravity of the disk?

    I agree with your answers until the last part, where you say 0.00816/.64 = 0.01266 m I think you've just missed a zero, so it would be 0.001266 m Check it by adding the two depths and multiplying by the base area to give the original volume.
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    Calculating max. speed of car over humpback bridge before it leaves the ground?

    I think my problem is assuming that the car could take off at any point as it was going up the humpback, as long as it had enough speed. For example if you take a point before the apex and instantly accelerate the car up to a large speed along the tangent - it would leave the track, you...
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    Calculating max. speed of car over humpback bridge before it leaves the ground?

    So Rcos(x) would just be R? the thing is with this I think is that the further from the peak of the bridge you get, the smaller the component of mg is acting towards the centre, therefore a smaller speed (v) is needed, which to me doesn't make sense (mainly because there is no mention of this...
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    Calculating max. speed of car over humpback bridge before it leaves the ground?

    Homework Statement A car travels over a humpback bridge of radius of curvature 45m, what is the max speed it can reach before the wheel lose contact with the road? Homework Equations mg - R = (mv^2) / r The Attempt at a Solution When the car is about to lose contact with...
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    Finding tension in a cable of a accelerating lift

    Thanks, as long as I'm right. I'll make it simpler for myself next time.
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    Finding tension in a cable of a accelerating lift

    So: mg - T = -(-0.1)m T = m(g - 0.1) T = 800 x 9.7 = +7760N
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    Finding tension in a cable of a accelerating lift

    I think what I've done is work out the force applied to the lift to produce that outcome. In my equation: T + mg = -(-0.1)m The value of T could be positve or negative. Doesn't the negative value just tell me that the force applied on the lift from the tension in the wire is in the...
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