IGCSE/GCSE/O & A Level/IB/University Student Forum
		Qualification => Subject Doubts => GCE AS & A2 Level  => Sciences => Topic started by: nox_fjmoony on May 18, 2010, 10:53:06 am
		
			
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				So I was solving the physics paper-1 paper for may/june-2009 and I had problems with these questions:
 1,5,6,7,15,18,20,27 and 29.
 
 I'd really appreciate if you could explain these to me! Like I can't seem to arriving to the correct answer. Any help would most certainly be appreciated.
 I'm attaching the question paper along with this post. Yeah.
 
 I'd also appreciate some tips on finishing the exam within the 1hour time duration. : )
 Thanks all.
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				I got more questions 
 OCT/NOV 2005
 
 21 A wire stretches 8 mm under a load of 60 N.
 A second wire of the same material, with half the diameter and a quarter of the original length of
 the first wire, is stretched by the same load.
 Assuming that Hooke’s law is obeyed, what is the extension of this wire?
 A 1 mm B 4 mm C 8 mm D 16 mm
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				So I was solving the physics paper-1 paper for may/june-2009 and I had problems with these questions:
 1,5,6,7,15,18,20,27 and 29.
 
 I'd really appreciate if you could explain these to me! Like I can't seem to arriving to the correct answer. Any help would most certainly be appreciated.
 I'm attaching the question paper along with this post. Yeah.
 
 I'd also appreciate some tips on finishing the exam within the 1hour time duration. : )
 Thanks all.
 
 
 Q1) from km to m its *1000
 from m to mm its also *1000
 therefore from km to mm its *1000000
 which is 10^6   so its D
 
 Q5) its D
 for the displacement-time graph  the slope is equal to the velocity
 if u look at D...the slope increasing  which means the velocity is increasing and thats whats happeneing when the object starts falling its velocity increases....but in C the slope id decreasing which means that the velocity is decreasing which is wrong....and then for D the line is straight which shows that velocity is constant,
 
 Q6) rememeber that only when the velocity is a HORIZONTAL STRAIGHT LINE then the displacement time graph would be in an INCREASING STRAIGHT LINE...so before "t1" its a straight line so exclude A
 then...velocity is decreasing,...if u look at C its the only one which has a a straight line in the begginning and then a decreasing slope.....like i mentioned before decreasing slope of displacement-time graph= decreasing velcoity so its C
 
 Q7) unless there is a force acting on the system then there is acceleration.......first law says: that the particle stays at rest or moves in a constant speed, unless a force act on it.
 
 Q15)E=mgh
 wen tap opens
 half of y is filled
 which means
 m/2 n h/2 also
 so it becomes
 mgh/4
 ans is B :)
 
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				I got more questions 
 OCT/NOV 2005
 
 21 A wire stretches 8 mm under a load of 60 N.
 A second wire of the same material, with half the diameter and a quarter of the original length of
 the first wire, is stretched by the same load.
 Assuming that Hooke’s law is obeyed, what is the extension of this wire?
 A 1 mm B 4 mm C 8 mm D 16 mm
 
 
 
 this is simple c :
 F=Ke lets find K first
 60=k /(8/1000)  divide by 1000 to change from mm to m
 k=7500
 since the forces used are same so we could use this:
 F=Ke
 let the new extension be "z"
 ke=kz
 7500* (8/1000)=7500 *z
 60/7500=z
 0.008 m=z
 0.008 *1000= 8mm=z
 
 hope u got it. :D
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				Hey Halosh, thanks a lot for the help! Though I still have some problems with understanding when a slope is decreasing and when it is increasing >_<
 
 Could you please help out? Anyone?
 Aaand, I also have trouble with question number 13 here, yeah.
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				Hey Halosh, thanks a lot for the help! Though I still have some problems with understanding when a slope is decreasing and when it is increasing >_<
 
 Could you please help out? Anyone?
 Aaand, I also have trouble with question number 13 here, yeah.
 
 
 
 velcity time graph:
 1) if its a horizontal straight line = displacement is a straight steeping upwards line
 2)if its a straight steeping line = displacement is a curve
 3) if object is falling down= velocity increases= displacement time graph has a slope
 slope=velocity
 as velocity increases, slope must increase also and viceversa
 got it?
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				Hey thanks : )
 Really appreciate all the help. Best of luck with your exams, if you're giving any right now that is. Thank you very very much
 :D
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				q 15 and 21 june 2009
			
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				q 15 and 21 june 2009
 
 
 21 divide the graph into different regions.
 the first part is a rectangle then a square then a trapezium.
 15 i seriously dont get
 
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				Guys plz question 23 in the attached paper :D
			
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				the frequency of uv rays vvaries from 10^15 to 10^17 Hz
 the higher the wavelength the lower the frequency...
 so we choose the least frequency..
 which is 10^15=10^x
 x=15
 
 By the way u know how to answer q13,14
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				yeh question 13 if u hear the word equilibrium look for a closed triangle, which is R & S
 q14 it says from the middle of the door so 12= F x 0.4 and u will get D
 
 By the way u answered for me the wrong question ;) I meant number 23 not 22 ;)
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				sorry wrong paper
 
 and my question was wrong too :S
 do u know how to answer q 13 , 14 in paper 11 oct 2009??
 
 for q23 i can't see the indices of the mass ...
 but anyways..u would require the formula ke = 1/2 mv^2