Author Topic: paper 1 physics HERE ONLY~!!!!!!!  (Read 12546 times)

Offline thisishard

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #60 on: June 09, 2009, 04:16:23 pm »
Can some1 explain wavefronts in water i cant get them :S!! May/June 2007 i think 30-35q

nid404

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #61 on: June 09, 2009, 04:19:30 pm »
Can some1 explain wavefronts in water i cant get them :S!! May/June 2007 i think 30-35q

specify the question plz

but basically a wavefront is a line joining in phase points in a wave such as two crests or two troughs.

Offline sweetie

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #62 on: June 09, 2009, 04:19:45 pm »
DOUBT!!!!!!!!!!!!
QUE.37 MAY08????????????
WY IS IT "C" NUT "D"???

Offline samin6n

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #63 on: June 09, 2009, 04:21:48 pm »
now i get it...thnk u soo much! ;D :D ;D

Offline Ghost Of Highbury

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #64 on: June 09, 2009, 04:23:07 pm »
DOUBT!!!!!!!!!!!!
QUE.37 MAY08????????????
WY IS IT "C" NUT "D"???
i am confused in this too

nid404 --- help
divine intervention!

nid404

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #65 on: June 09, 2009, 04:25:23 pm »
DOUBT!!!!!!!!!!!!
QUE.37 MAY08????????????
WY IS IT "C" NUT "D"???

k. i'll use values to explain

take the voltage from the source to be 20V
so current in the first circuit would be-20/200(combined resistance)=0.01
so voltage across each resistor would be 10V(0.01x100) since V=IR

In the second circuit current would be 20/190=0.105
so voltage across 90ohms would be=0.105x90=9.45
and voltage across 100ohms=0.105x100=10.05
so voltage across the higher resistor increases

hope u got that

Offline noor92

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #66 on: June 09, 2009, 04:27:07 pm »
You guys can someone explain May/June 03 Q 17, does a small temp. rise mean high thermal capacity? The answer according to mark schemes is A.

Offline thisishard

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #67 on: June 09, 2009, 04:27:14 pm »
may/june 2007 question 20 what should i do to answer these kind of questions?

Offline Ghost Of Highbury

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #68 on: June 09, 2009, 04:28:01 pm »
ohh tks

cud this be the possible explanation
V = I*R
I = V/R
R decreases - I increases

when I increases  V increases too///

(i don't think so)
divine intervention!

nid404

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #69 on: June 09, 2009, 04:30:06 pm »
You guys can someone explain May/June 03 Q 17, does a small temp. rise mean high thermal capacity? The answer according to mark schemes is A.

yes thermal capacity=energy required to raise the temperature of the entire mass of substance by 1oC. So lesser the temp rise more the thermal capacity.

Offline Ghost Of Highbury

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #70 on: June 09, 2009, 04:31:26 pm »
thermal capacity = mass * specific heat capacity

specific heat capacity = heat received / (mass * temp change)


if the temp change is the least the specific heat capacity will be the greatest and therefore the thermal capacity will be the greatest
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Offline thisishard

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #71 on: June 09, 2009, 04:32:42 pm »
answer me!! >:(

nid404

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #72 on: June 09, 2009, 04:35:10 pm »
ohh tks

cud this be the possible explanation
V = I*R
I = V/R
R decreases - I increases

when I increases  V increases too///

(i don't think so)

what r trying to explain??

@thisishard: pls be patient im not a robot.

Offline Ghost Of Highbury

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #73 on: June 09, 2009, 04:36:44 pm »
@nid - its k...i guess i'm wrong...thanks anyway

@ thisishard - i think the wavelength increases because the frequency doesn't change

speed = frequency * wavelength

speed increases - frequency constant - wavelength increases...
nid404 can help u

i have few problems in these type of questions too

divine intervention!

nid404

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Re: paper 1 physics HERE ONLY~!!!!!!!
« Reply #74 on: June 09, 2009, 04:40:06 pm »
may/june 2007 question 20 what should i do to answer these kind of questions?

when the wave moves from shallow water to deep water, wavelength increases and the wavefronts move towards the normal. So the ans is C.

Tip-try drawing a normal to the wavefront and check whether refraction is towards the normal or away. if towatds then water is deeper, if away then waves have moved into shallow water