Author Topic: Physics CIE help  (Read 12295 times)

Offline halosh92

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Re: Physics CIE help
« Reply #30 on: April 11, 2010, 07:02:20 pm »
Paper 2?

oops i forgot to add that...yes paper 2
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Offline halosh92

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Re: Physics CIE help
« Reply #31 on: April 11, 2010, 07:13:36 pm »
2007 oct/nov
q5a
could someone plz sketch it :SSSS
1/2 the intensity is sqrt(1/2)=0.707 times the amplitude
The sum of the two smaller waves is the bigger one

thankyou but when they say the wave has a phase difference of 60 degrees..wat do they mean exactly????
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Offline astarmathsandphysics

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Re: Physics CIE help
« Reply #32 on: April 11, 2010, 08:31:34 pm »
They are 60/360=1/5 of af a wavelength apart

Offline tmisterr

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Re: Physics CIE help
« Reply #33 on: April 12, 2010, 10:52:32 am »
Thanks astar. 1 more, q 28 on the attached paper

Offline astarmathsandphysics

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Re: Physics CIE help
« Reply #34 on: April 12, 2010, 11:03:50 am »
When I get home

Offline astarmathsandphysics

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Re: Physics CIE help
« Reply #35 on: April 12, 2010, 11:13:27 pm »
C - for destructive interference the path difference must be a whole number of wavelengths plus an extra half wavelength

Offline halosh92

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Re: Physics CIE help
« Reply #36 on: April 13, 2010, 07:24:12 am »
C - for destructive interference the path difference must be a whole number of wavelengths plus an extra half wavelength
could you explain this furthur please?
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Re: Physics CIE help
« Reply #37 on: April 13, 2010, 07:44:36 am »
could you explain this furthur please?

constructive interference- happens when waves are in phase...and so the path difference is a multiple of ?...
equation for path diff of constructive: n?, where n=1, 2,3....

destructive interference: happens when waves are out of phase, and so the path difference is a multiple of half ?
equation for path diff of destructive= (0.5+n)?

therefore the only possible answer is C...

got it?

Offline sweetie

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Re: Physics CIE help
« Reply #38 on: April 14, 2010, 05:51:18 pm »
hey ppl,
when a graph line is sloping downwards, it has a neg. gradient so if we had to cal. the value of the gradient will it be written as  " -x" or " x"???????

Offline halosh92

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Re: Physics CIE help
« Reply #39 on: April 14, 2010, 06:17:42 pm »
constructive interference- happens when waves are in phase...and so the path difference is a multiple of ?...
equation for path diff of constructive: n?, where n=1, 2,3....

destructive interference: happens when waves are out of phase, and so the path difference is a multiple of half ?
equation for path diff of destructive= (0.5+n)?

therefore the only possible answer is C...

got it?

thx alot...but wats the "?" in ure explanation?
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Amr Fouad

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Re: Physics CIE help
« Reply #40 on: April 14, 2010, 06:52:13 pm »
thx alot...but wats the "?" in ure explanation?

oh lol sorry SF cant comprehend that lol

i meant Londa..the wavelength symbol..substitute ? with Londa

Offline *Hope*

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Re: Physics CIE help
« Reply #41 on: April 18, 2010, 06:33:18 am »
11) sum of momentum before collision=sum of momentum after collision

ball A
mVA- mUA
ball B
mVB-(-mUB)(opp  direction )

p of ball A=ball B (for elastic collision)

mVA- mUA=mVB-(-mUB)
VA-UA=VB+UB
VA-VB=UB+UA
why did u take the momentum of A alone and B alone, shouldn't we take A and B before collision and A and B after considering the signs so like mUa-mUb=mVa+mVb??
plz explain nid
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Offline Saladin

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Re: Physics CIE help
« Reply #42 on: April 18, 2010, 07:44:33 am »
hey ppl,
when a graph line is sloping downwards, it has a neg. gradient so if we had to cal. the value of the gradient will it be written as  " -x" or " x"???????

-x

Offline cashem'up

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Re: Physics CIE help
« Reply #43 on: April 18, 2010, 11:41:01 am »
hey i have doubt in this question its wo4 20 have uploaded

Offline astarmathsandphysics

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Re: Physics CIE help
« Reply #44 on: April 18, 2010, 12:01:04 pm »
-x