IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: cashem'up on May 18, 2010, 03:39:18 pm
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hey guys a very tough question q34 wo5.....so damn confusing....chek the gradient is highest at B so shouldnt it be Answer.....but Ans iis C
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hey guys a very tough question q34 wo5.....so damn confusing....chek the gradient is highest at B so shouldnt it be Answer.....but Ans iis C
gradient is not highest at B its highest at C............draw a tangent and create your own points and check C has the largest gradient....steeper...larger the gradient
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Hey which year is this? 2005? If so is it the oct/november or the may/june one?
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Hey which year is this? 2005? If so is it the oct/november or the may/june one?
2005 nov
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but how if u see isnt it steepest at B and also why do u draw tangent and also help me with w06 q21 thanks........ ;D ;D ;D
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but how if u see isnt it steepest at B and also why do u draw tangent and also help me with w06 q21 thanks........ ;D ;D ;D
no no the higher the line the steeper it is the more is the gradient :D
draw a tangent just for ure own convenience so that u get the idea nothin more.
Q21) pressure of water + pressure of oil = total pressure
PHG +PHG = 17.5*10^6 (*10^6 because we want to change megametre to metre)
(1000 * (2000-x) *9.8) + (830 * x *9.8) = 17.5*10^6
solve this equation
x= 1260.5
which is nearest to answer D
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I'll ask my friend from A2 for nov 05
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no no the higher the line the steeper it is the more is the gradient :D
draw a tangent just for ure own convenience so that u get the idea nothin more.
Q21) pressure of water + pressure of oil = total pressure
PHG +PHG = 17.5*10^6 (*10^6 because we want to change megametre to metre)
(1000 * (2000-x) *9.8) + (830 * x *9.8) = 17.5*10^6
solve this equation
x= 1260.5
which is nearest to answer D
hey thanks buddy....pheew.....it helped alot.........
but m still confused wid first one.... ???
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I'll ask my friend from A2 for nov 05
yea please if u can ......
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gradient of V-I graph is NOT equal to the resistance unless it is an ohmic resistor at constant temp. I/V is highest at point C, or the gradient of the line from the ORIGIN TO THE POINT C is greatest there for V/I will be smallest.
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Could you illustrate that on the graph. I am still not clear. Phy is not too good a subject of mine
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someone please explain question 14 of november 09/12...
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Nov 09/12
Q14) momentum before spring was released=0
so momentum after releasing would also be 0
momentum of 2kg trolley= 4kgm/s
momentum of 1kg trolley would be= -4kgm/s (since sum has to equal to zero)
mv=-4
velocity of 1kg trolley will be 4m/s in the opp direction
total k.e= 1/2 X 2 X 22 + 1/2 X1 X42
=4 + 8
=12J
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Nov 09/12
Q14) momentum before spring was released=0
so momentum after releasing would also be 0
momentum of 2kg trolley= 4kgm/s
momentum of 1kg trolley would be= -4kgm/s (since sum has to equal to zero)
mv=-4
velocity of 1kg trolley will be 4m/s in the opp direction
total k.e= 1/2 X 2 X 22 + 1/2 X1 X42
=4 + 8
=12J
thanks so much nid!!!! hey if you have some last minute tips for physics, please tell! oh and the formula for phase difference, (2n+1)lambda/2, what does n stand for??? i've totally forgotten it
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You're welcome.
Which eqn is this? :S
lol i have no idea
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it's for phase difference...you know, if two points on a wave are in phase, their phase difference is given by n(lambda)....and if they're out of phase, their phase difference is given by (2n+1)lambda/2...where lambda is the wavelength...
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Could you illustrate that on the graph. I am still not clear. Phy is not too good a subject of mine
ohh can't illustrate now, kinda busy...but let me try elaborate. look at the graph, draw a line from the origin to A, another from the origin to B, another from the origin to C, and another from the origin to D. as you can see, the line from the origin to C has the highest gradient right? so this means change in y(I)/change in x(V) is greatest right? since resistance is the reciprocal of this I/V that is V/I, it will be smallest if I/V is greatest thus C.
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ohkay thanks...i get it now :)
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guys..one question..
when a metal is heated.. i.e. it's temperature increases... it's resistance decreases right???
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guys..one question..
when a metal is heated.. i.e. it's temperature increases... it's resistance decreases right???
no no!!!!
when temp increase resistance increase because more energy more collisions so its more difficult for current to pass.
thats for all metals
ure case happens only with thermistors ;D
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can someone explain Q25 (p12 nov 2009)
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sinx=nw/d
d=0.001/300=3.3*10^-6
w=450*10^-9
sin x =n*5/37<1
n<37/5=7.4
n=7