Author Topic: Edexcel PHYSICS Doubts  (Read 137810 times)

Offline Saladin

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Re: Edexcel PHYSICS Doubts
« Reply #75 on: May 31, 2010, 02:03:55 pm »
well in a levels physics paper 5(planning,Annalysis and evaluation) we have only 2 questions to answer. format for question number can be seen on any of the previous years question paper
http://www.xtremepapers.net/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_s07_qp_5.pdf

I humbly apologize, I don't do A2 Physics.

Offline seth99

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Re: Edexcel PHYSICS Doubts
« Reply #76 on: May 31, 2010, 02:05:40 pm »
its ok  :D and ya thanx for wasting my time  ;)

Offline ikh

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Re: Edexcel PHYSICS Doubts
« Reply #77 on: May 31, 2010, 03:53:46 pm »
Could some one do help me with edexcel exam wizard qs for unit 2 - waves - q93

HOw is the amplitude and maximum displacment calculated ???

Offline Meticulous

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Re: Edexcel PHYSICS Doubts
« Reply #78 on: May 31, 2010, 04:00:29 pm »
Please post the question  here.

Offline ikh

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Re: Edexcel PHYSICS Doubts
« Reply #79 on: May 31, 2010, 04:10:13 pm »
93.   The diagram shows part of a stretched slinky spring and the same section of the spring when a longitudinal wave is travelling along it.
 
 
   The dotted vertical lines show the positions of two coils which at this moment are undisplaced.
   Mark on the lower diagram a compression C and a rarefaction R
   Measure the wavelength of the wave
Wavelength ...
   Mark on the lower diagram a coil with maximum displacement, M.
   Measure the amplitude of the wave, i.e. the displacement of coil M.
Amplitude ...
(Total 4 marks)


couldnt get the pic here so attached file


Offline Meticulous

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Re: Edexcel PHYSICS Doubts
« Reply #80 on: May 31, 2010, 04:12:58 pm »
Amplitude=max displacement

Offline ikh

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Re: Edexcel PHYSICS Doubts
« Reply #81 on: May 31, 2010, 04:20:59 pm »
Amplitude=max displacement

i do reliase amplitude = displacment but how do you measure the amplitude in this graph (this is not a transverse graph but a longitudinal one displayed as a sinisoudial one) please explain how exactly to measure.

Thanks in advance




« Last Edit: May 31, 2010, 04:32:55 pm by ikh »

Offline ikh

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Re: Edexcel PHYSICS Doubts
« Reply #82 on: May 31, 2010, 07:28:29 pm »
plz help it is an important qs....

Offline vanibharutham

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Re: Edexcel PHYSICS Doubts
« Reply #83 on: May 31, 2010, 09:12:49 pm »
@ ikh

Longitudinal waves have compressions and rarefactions and im sure you know that the distance between the centres of two compression or two rarefactions is the wavelength.

However, to work out amplitude you must know that at the centre of the rarefaction or at the centre of a compression the displacement is zero. Using that and the slinky given at the rest position, you can work out the distance between the maximum displacement of the slinky.
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Offline vanibharutham

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Re: Edexcel PHYSICS Doubts
« Reply #84 on: May 31, 2010, 09:14:15 pm »
@ anyone:

When Supernova 1987A was detected on Earth, neutrinos emitted in the explosion arrived about 20 hours earlier than the light, even though both were created at the same instant. How is this consistent with the idea that nothing can travel faster than the speed of light? (Hint: space is not empty)

What I'm guessing, though not sure, is that because "space is not empty" the light rays must be refracting in the somewhat denser medium and must be slowing down. However, the neutrinos, being particles, must have sped up and thus reached the earth before the light reached us. However, since nothing is faster than the speed of light, neutrinos only reached the earth because light slowed down, the consistency of the idea that nothing can travel faster than light is true.
A genius is 1% intelligence, 99% effort.

Offline ikh

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Re: Edexcel PHYSICS Doubts
« Reply #85 on: June 01, 2010, 02:29:25 pm »
@ ikh

Longitudinal waves have compressions and rarefactions and im sure you know that the distance between the centres of two compression or two rarefactions is the wavelength.

However, to work out amplitude you must know that at the centre of the rarefaction or at the centre of a compression the displacement is zero. Using that and the slinky given at the rest position, you can work out the distance between the maximum displacement of the slinky.

could u plz elaborate a bit more if i assume the centre of the rarefaction or at the centre of a compression the displacement is zero then what i am supposed to measure using the slinky at rest position....

i would appreciate if u could use the uploaded file and put marks wht exactly to measure as that would be really helpful

Thanks

Offline Saladin

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Re: Edexcel PHYSICS Doubts
« Reply #86 on: June 01, 2010, 07:27:42 pm »
could u plz elaborate a bit more if i assume the centre of the rarefaction or at the centre of a compression the displacement is zero then what i am supposed to measure using the slinky at rest position....

i would appreciate if u could use the uploaded file and put marks wht exactly to measure as that would be really helpful

Thanks

You can't actually. You have to measure from compression to compression or rarefaction to rarefacton.

Offline student

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Re: Edexcel PHYSICS Doubts
« Reply #87 on: June 01, 2010, 07:43:17 pm »
Seems an easy momentum question..

A 4MeV particle collides head-on with a stationary proton, and its kinetic energy is reduced to 1MeV. What is the mass of the particle? Mass of a proton = 1.6726*10-27kg.

But I can't get it.
« Last Edit: June 01, 2010, 07:47:55 pm by student »

Offline ABF

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Re: Edexcel PHYSICS Doubts
« Reply #88 on: June 01, 2010, 09:38:20 pm »
does anyone have any notes on the nature of light?please i need it urgently..

Offline Meticulous

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