Physics: Post your doubts here!

[Wes Allen]

Use centre of gravity
So at top : mgh = 500 x (0.8 + 0.3)
At bottom : mgh = 500 x 0.2
So the answer is 450N

Thanks!

 

[amal sharkawi]

CAN ANYONE ANSWER THIS QUESTION PLZ ??

 

[The Sarcastic Retard]

View attachment 57170

CAN ANYONE ANSWER THIS QUESTION PLZ ??

B?

 

[ahmedish]

here http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s14_qp_23.pdf
why in 6 c is the phase difference 0? also can someone explain phase and path difference because i dont really get them

 

[Jinosupreme]

Anyone can help in question 3B? Pls thanks!!!

 

[ahmedish]

go to
http://physics-ref.blogspot.com/2014/10/9702-june-2014-paper-23-worked.html

it just says phase difference = 0 not why

 

[ahmedish]

If i have a value of 6453 and uncertainty of 5%
how should I write the final answer?
6400+_ 300?
I got this as 5% of 6453 is 322.65, to 1 s.f is 300
then i got 6400 as in to the same "tens" like thats 3 hundred, so the value should be to the hundreds and is 6400
bc in ones with decimal if the uncertainty is 0.4 we write the value to 1 dp
is this correct?

 

[harsie]

2015/22/m/j solve Q 2 and 5 with explanation .

 

[ahmedish]

View attachment 57170

CAN ANYONE ANSWER THIS QUESTION PLZ ??

B
cos I = A squared
2I = A squared
A = square root 2 I
so only 1.4 not 2

 

[ashcull14]

(c) On Fig.4.1, mark a position of the pivot P for the piston to have
(i) maximum speed (mark this position S), [1]
(ii) maximum acceleration (mark this position A).

 

[Shujaat Khan]

P

View attachment 57183
(c) On Fig.4.1, mark a position of the pivot P for the piston to have
(i) maximum speed (mark this position S), [1]
(ii) maximum acceleration (mark this position A).

According to me max speed should be half sphere end horizontal at either left or right. Think of it as an shm max kinetic energy is always at equilibrium position.

As for acceleration half sphere vertical logically( up or down)

 

[Shujaat Khan]

If i have a value of 6453 and uncertainty of 5%
how should I write the final answer?
6400+_ 300?
I got this as 5% of 6453 is 322.65, to 1 s.f is 300
then i got 6400 as in to the same "tens" like thats 3 hundred, so the value should be to the hundreds and is 6400
bc in ones with decimal if the uncertainty is 0.4 we write the value to 1 dp
is this correct?

Why not use power10.
(6.45+- 0.323)*10^3
Or to 2sf both as you seem fit

 

[ahmedish]

Why not use power10.
(6.45+- 0.323)*10^3
Or to 2sf both as you seem fit

uncertainty is given to 1 s.f only

 

[nehaoscar]

Please explain why the electric field points upwards as the answer...

 

[Kool boy]

Any idea about physics paper 34

 

[Shujaat Khan]

uncertainty is given to 1 s.f only

That's so wrong! Who told you that? Don't do that mistake in exams they will penalize you for this.
You never came across an uncertainty with +- 0.25 or +-1.5 in any question paper? You must keep working more papers then.
These are 2s.f btw

More info here http://facultyfiles.deanza.edu/gems/lunaeduardo/UncertaintyandSignificantFig.pdf

 

[ahmedish]

That's so wrong! Who told you that? Don't do that mistake in exams they will penalize you for this.
You never came across an uncertainty with +- 0.25 or +-1.5 in any question paper? You must keep working more papers then.
These are 2s.f btw

More info here http://facultyfiles.deanza.edu/gems/lunaeduardo/UncertaintyandSignificantFig.pdf

http://papers.xtremepapers.com/CIE/...A and AS Level/Physics (9702)/9702_w09_er.pdf
check variant 22 Q1cii

 

[Shujaat Khan]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w09_er.pdf
check variant 22 Q1cii

Strange. Either my physics teacher was in the wrong or years have changed and so did answers? I need to confirm this with more teachers and friends , could you provide me the question for the "attached" screenshot?
Also thanks for the info really didnt know about this throughout 2years I've been using 2sf

 

[ahmedish]

Strange. Either my physics teacher was in the wrong or years have changed and so did answers? I need to confirm this with more teachers and friends , could you provide me the question for the "attached" screenshot?
Also thanks for the info really didnt know about this throughout 2years I've been using 2sf

Its June 2014 (Doesnt get any more recent than that) V22 Q2bii

 

[shahzaib9291]

Guys can someone till me what type of practical could come for capacitors?