Physics: Post your doubts here!

[goodluckayesha]

5ci)i1/i2=(a1/a2) ^2
1/i2=(9/4)
i2=4/9

thnq u soo much

 

[goodluckayesha]

thnq u soo much

wht abt part cii ??

 

[Nidz-Ahmed]

ph. http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s07_qp_2.pdf 4 d(i) Can Some one Specify the shape of the graph

 

[falcon678]

guys can anyone explain me question 6 (c) ?

 

[gary221]

guys can anyone explain me question 6 (c) ?

6 c) Energy = 5.7 * 10^3 eV ---> convert the eV into Joules
1 eV = 1.6 * 10^-19 J
So, 5.7 * 10^3 eV ----> (5.7 * 10^3) * 1.6 * 10^-19 = 9.12 × 10^–16 J

So, kinetic energy = 9.12 × 10^–16 J
Kinetic energy = 1/2 * m * v^2
9.12 × 10^–16 = 0.5 * (9.11 * 10^-31) * v^2

So, v^2 = (9.12 × 10^–16) / (0.5 * 9.11 * 10^-31)
v = 4.47 * 10^7 m/s

Hope u gt it!!!

 

[Sapphires]

I need help with Questions 4b and 4d, plz. Thank you.
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s11_qp_41.pdf

 

[Manobilly]

Q2 c The shape of the graph.

 

[hellangel1]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s10_qp_21.pdf
I knw its very basic, but can anyone plz help with question 3 part b(ii) and question 5 part c

 

[elwad yousef]

hello can anybody help me with 9702/21/m/j/09 Q1 b i forgot uncertainty thank you !

 

[goodluckayesha]

plzzzzzzzzz explain!!!!!!!!!!!

 

[goodluckayesha]

Does any1 have guess papers for phy chm bio??

 

[syed1995]

plzzzzzzzzz explain!!!!!!!!!!!

Extension is directly propotional to force..

let the Force needed to get extension x be F..

So horizontal component of S1 = Fcos60
same with S2 FCos60

FCos60+FCos60 = F .. so the extension of S3 would be x.. what's the answer?

 

[abruzzi]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s12_qp_23.pdf
I need help with question 1 c(ii).. how do I draw the scale diagram?

 

[ahmed abdulla]

any help ? qn 6 (b) and (c) i and iv .....
isnt it 90 degree ? in MS it shows zero rad! and what does the sign in last question mean
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_23.pdf
Tkp

 

[hamzaateeq]

What is the phase difference between these two points?
Pls help

 

[syed1995]

any help ? qn 6 (b) and (c) i and iv .....
isnt it 90 degree ? in MS it shows zero rad! and what does the sign in last question mean
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_23.pdf
Tkp

In stationary wave.. Particles in the same segment/ between 2 adjacent nodes, are in phase. Particles in adjacent segments are in anti-phase.


While In Progressive wave.. All particles within one wavelength have different phases.

bii ) 180 degrees.. since it's progressive and half wavelength apart.

ci) 0 degrees.. since it's a stationary wave and both are in the same segment.

iv.. it is just a variable.. which doesn't matter..

If the wave given has time period x.. you need to draw a wave with 0.25x time period.. As F=1/T F=1/0.25 simple draw a wave with 4 times the frequency... but same amplitude.

 

[syed1995]

What is the phase difference between these two points?
Pls help

Is it progressive or stationary?

 

[Sapphires]

I need help with Questions 4b and 4d, plz. Thank you.
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_41.pdf

Please help me with these.
Thank you.

 

[goodluckayesha]

Extension is directly propotional to force..

let the Force needed to get extension x be F..

So horizontal component of S1 = Fcos60
same with S2 FCos60

FCos60+FCos60 = F .. so the extension of S3 would be x.. what's the answer?

the answer is correct n thnq u soo much for the explanation but the mark scheme says
" same force F in both springs
resultant is 2F cos60 or scale drawing
resultant F so extension is x (maximum 1/3 marks if x is used alone without reference to kx)"
this red part wht wud b use of kx???

 

[syed1995]

the answer is correct n thnq u soo much for the explanation but the mark scheme says
" same force F in both springs
resultant is 2F cos60 or scale drawing
resultant F so extension is x (maximum 1/3 marks if x is used alone without reference to kx)"
this red part wht wud b use of kx???

Yea.. you need to give the refrence.. that since F is directly proportional to extension .. the extension will be same... F=kx where k is constant... I just solved the question .. that depends on the marks of the question ...