Physics: Post your doubts here!

[kiara15]

any1 tel me how to do quest 2 part c in http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s09_qp_5.pdf

 

[Soldier313]

A loudspeaker incident and the sound received by a microphone or source detector. We put the detector as close to the glass to avoid reflection of sound and the detector behaves in such a way we want to know the details about the sound wave at the glass window, my thought though, I am doing it right now btw, what about the second question where they ask to draw best and worst fit line I don't get it

yeah i don't get the way we have to insert the vacuum pump and the strain gauge :/
best fit line is the one that passes through all the plotted points except the anomalies
worst acceptable line is the one that passes through all the error bars (from the top of the first error bar to the bottom of the last error bar, or vice versa )

 

[samia khalid]

Re: Physics Help here! Stuck somewhere?? Ask here!
please can anyone post any solved paper5, q2 here ...i have problem with plotting the error bars. plzzzz help anyone
my prayers will always be for u....ia

 

[TaffsAsLevel]

yeah i don't get the way we have to insert the vacuum pump and the strain gauge :/
best fit line is the one that passes through all the plotted points except the anomalies
worst acceptable line is the one that passes through all the error bars (from the top of the first error bar to the bottom of the last error bar, or vice versa )

I don't think that is anything necessary to write because data collection is 5 marks, 1 for drawing, 1 for how to measure the value of the independent variable, 1 for dependent variable, and 2 marks to measure the other controlled variables. There is a vacuum pump somehow but I don't know how it works but it's enough to say you need the vacuum pump since all are one mark each. Simply mention it in bullet points as my revision guide suggested rather than how you actually do it by hand just say the apparatus for whichever it is.

 

[Soldier313]

I don't think that is anything necessary to write because data collection is 5 marks, 1 for drawing, 1 for how to measure the value of the independent variable, 1 for dependent variable, and 2 marks to measure the other controlled variables. There is a vacuum pump somehow but I don't know how it works but it's enough to say you need the vacuum pump since all are one mark each. Simply mention it in bullet points as my revision guide suggested rather than how you actually do it by hand just say the apparatus for whichever it is.

but i think it is necessary to include it in the diagram as far as i know :/
Thanx though!

 

[rehan751]

Guys my grade components in AS are AAC. Im hoping to get AA in A2 so can I get an A* with all As and a C in Paper 3?

 

[TaffsAsLevel]

but i think it is necessary to include it in the diagram as far as i know :/
Thanx though!

Nope, "arrangement of apparatus and procedures to be followed" procedures can be described just by the apparatus for which quantity

 

[daredevil]

in that 31 questions

Q25) Drawing the waveforms, l=1/4wavelength in X and l=1/2 wavelength in Y. As the speed of sound is constant, the ratios of the frequencies should be reciprocal to the ratio of wavelengths, that would be frequency of X:Y = 1:2. So frequency of Y is double of the frequency of X.
Q31) Conduction wires conduct due to mobile electrons, so C and D are incorrect. The movement of electrons random, so B is eliminated. A is correct.

3. Q23) I'm not entirely sure of this but the extension is denoted by W/k. Now P and Q have identical spring constants so total extenion = 2. Now PQ and R are taken in series so product over sum gives us the answer.

4. Q12) SOMEONE PLEASE SOLVE THIS FOR ME TOO.

5. Q12) R1 and R2 both act against the weight of the frame so their magnitude would be equal. T1 has a greater horizontal component than T2, the vertical one is in the same line of force as the weight and R for both and is not considered, so wire T1 is more tensed upp. More like how picture frames fall when you suspend them with too short a wire and they snap. Real life scenarios.

And I had a powercut scheduled in the middle so the 3 seperate posts. Sorry.

there is no current in the wire so what were you saying about the C and D being incorrect because curent only passes with mobile electrns?

 

[Mishaa]

in that 31 questions
there is no current in the wire so what were you saying about the C and D being incorrect because curent only passes with mobile electrns?

Delocalised or 'mobile' electrons are called so because they are never stable or in a fixed place. They move about. That being my point here on eliminating the two options, Miss T.

 

[Soldier313]

Nope, "arrangement of apparatus and procedures to be followed" procedures can be described just by the apparatus for which quantity

Owhhh okay....hmmm.... although our teacher told us that it is necessary to include all the apparatus in the diagram!
Thanx a lot for clarifying that....

 

[daredevil]

Delocalised or 'mobile' electrons are called so because they are never stable or in a fixed place. They move about. That being my point here on eliminating the two options, Miss T.

hahahaha.... Meeeesshhaa! thanksuu xD

 

[hela]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_11.pdf Q12 A

 

[Yousif Mukkhtar]

Can anyone help in these questions: Q10. Q22.Q30
http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s03_qp_1.pdf

 

[daredevil]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_11.pdf Q12 A

i got help from a friend on that one...
its 120a = 120g - T (its F=ma for LHS and T is tension) --> for the barrel

80a = T - 80g ---> for the man

adding the 2 equaitons u get
200a = 40g
a = 1.962 [whn u take g=10ms^-2]

man is level with the barrel when both have covered the same distance:
18/2 = 9m [acceleration is same for both so both have travelled same distance]

2as = v2 - u2
2(1.962)(9) = v^2
v = 5.94 = 6 [approx.]

 

[Mairaxo]

Guys my grade components in AS are AAC. Im hoping to get AA in A2 so can I get an A* with all As and a C in Paper 3?

wow thats just like my grades in AS

 

[Mairaxo]

in paper 5 graph question .. do we hav 2 extrapolate the graph till origin or just til the points? i have no teacher so i need help !! and how many significant figures for all answers?

 

[hela]

Q25) Drawing the waveforms, l=1/4wavelength in X and l=1/2 wavelength in Y. As the speed of sound is constant, the ratios of the frequencies should be reciprocal to the ratio of wavelengths, that would be frequency of X:Y = 1:2. So frequency of Y is double of the frequency of X.
Q31) Conduction wires conduct due to mobile electrons, so C and D are incorrect. The movement of electrons random, so B is eliminated. A is correct.

3. Q23) I'm not entirely sure of this but the extension is denoted by W/k. Now P and Q have identical spring constants so total extenion = 2. Now PQ and R are taken in series so product over sum gives us the answer.

4. Q12) SOMEONE PLEASE SOLVE THIS FOR ME TOO.

5. Q12) R1 and R2 both act against the weight of the frame so their magnitude would be equal. T1 has a greater horizontal component than T2, the vertical one is in the same line of force as the weight and R for both and is not considered, so wire T1 is more tensed upp. More like how picture frames fall when you suspend them with too short a wire and they snap. Real life scenarios.

And I had a powercut scheduled in the middle so the 3 seperate posts. Sorry.

very very helpful thanks

 

[h4rriet]

Can anyone help in these questions: Q10. Q22.Q30
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s03_qp_1.pdf

10. F=4ma. a=F/4m. F(Y)=3m x F/4m = 3F/4.
22. F on each spring = W/3. F=kx. k=F/x=W/3x. x=F/k=W/W/3x=3x.
30. Average current=100+20=120/2=60. Q=It=60x8=480.

 

[Ahmad Zaeem]

I NEED A DIAGRAM FOR O/N 2011 p52 !! ..QS 1 ....NEED HELP PLEASE!!!
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w11_qp_52.pdf

 

[anishniroula]

can anyone help me with qno 2 of O/N 2011 paper 53. How to calculate uncertainity in V^2 . Please help me.