Biology; Chemistry; Physics: Post your doubts here!

[rabiafarooq101]

here pivot is Q and clockwise moment(distance QC *weight of lamina) will balance it.

THANKS

 

[luckywang]

Please explain the question attached!

something like this? then measure the angle of incident?

 

[luckywang]

what is p.d.s in C.R.O.? help pls...

somebody! answer this pls...

 

[Dukeofwin]

can u convert it to pdf?i can't open it..

HERE

 

[A star]

answer is B?

no D. need answers

 

[ashiqbal]

how are u guys preparing for P2??? i am really tensed!! My average score is 67-68, what can i do to make sure i dont lose that 7-8 marks???please help!

 

[Dukeofwin]

something like this? then measure the angle of incident?

This is the diagram to SHOW the critical angle! Not on how to measure it!

 

[luckywang]

no D. need answers

dont know... cant help... sorry...

 

[a.abid]

how are u guys preparing for P2??? i am really tensed!! My average score is 67-68, what can i do to make sure i dont lose that 7-8 marks???please help!

Go through the book and notes thoroughly and try to learn definitions and practice pastpapers.

 

[Dukeofwin]

how are u guys preparing for P2??? i am really tensed!! My average score is 67-68, what can i do to make sure i dont lose that 7-8 marks???please help!

SAME here,
The only phrase that the examiner report has from past few years is to read the question carefully!
I'm sure if you do it, the margin would decrease to 3-4 marks only

 

[A star]

i give answer first...
22=A?
26=A?
32=C?
34=D?
correct?

22=c
26=a
32=D
34=A
i think

 

[luckywang]

This is the diagram to SHOW the critical angle! Not on how to measure it!

then u wan draw a block then draw out the incident and refracted ray? then use sin i/sin r to find refractive index... then only use sin critical angle =1/refractive index? i think like that too long...
and that is describe an experiment? describe a student use a semi-circle glass block... move the ray until the refracted ray is 90 degree... cannot?

 

[Talhakhan]

Need help... Question 8
http://www.xtremepapers.com/papers/...onal O Level/Physics (5054)/5054_s08_qp_1.pdf

 

[luckywang]

22=c
26=a
32=D
34=A
i think

dont scare me man... i check the ms... my answer for 22 wrong only... answer is B...

 

[luckywang]

Need help... Question 8
http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf

lol... again? 0.3m x 2N=0.6Nm and it will turn clockwise... answer is A!

 

[ashiqbal]

HERE

place semi circular glass/ perspex block, then draw around it with pencil( so that it can be restored if moved)
then place two pins P1, P2 in straight line with the flat part of the semicircular glass block.
view from different angles until the two pins appear as one, then place another pin P3 from behind the circular part of the block so that the three pins appear as one. place another pin P4 behind it for accuracy.
draw line from P3 and P4 to flat part of block. draw normal at point where it touches block. measure angle from normal of line P3,P4 to get critical angle!

 

[Dukeofwin]

How to find the height in Question 2 (a)(ii)
November 2011 Theory

 

[a.abid]

Need help... Question 8
http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf

The answer is A because C is the centre of mass and Moment=force x perpendicular distance.Since weight acts downwards, QC will be the distance that is 0.30m.Now the answer will be 0.30x2=0.6Nm. clockwise moment

 

[luckywang]

place semi circular glass/ perspex block, then draw around it with pencil( so that it can be restored if moved)
then place two pins P1, P2 in straight line with the flat part of the semicircular glass block.
view from different angles until the two pins appear as one, then place another pin P3 from behind the circular part of the block so that the three pins appear as one. place another pin P4 behind it for accuracy.
draw line from P3 and P4 to flat part of block. draw normal at point where it touches block. measure angle from normal of line P3,P4 to get critical angle!View attachment 10673

woah! so detail! thanks!

 

[Dukeofwin]

place semi circular glass/ perspex block, then draw around it with pencil( so that it can be restored if moved)
then place two pins P1, P2 in straight line with the flat part of the semicircular glass block.
view from different angles until the two pins appear as one, then place another pin P3 from behind the circular part of the block so that the three pins appear as one. place another pin P4 behind it for accuracy.
draw line from P3 and P4 to flat part of block. draw normal at point where it touches block. measure angle from normal of line P3,P4 to get critical angle!View attachment 10673

Thanks, seems reasonable!