Physics: Post your doubts here!

[omaaaar]

Q3b) I am not sure, better Suchal Riaz help you
Q5b)
i)
2 = I ( 4 + 0.5 + 2.5 )
I = 0.29A
ii)
R across * J = (0.9/1) * 4 = 3.6 omega
V = IR = 0.29 * 3.6 = 1.03V
iii)
Same as ii) i.e is 1.03 as r do not need any value , We are asked reason too in next question
iv)
P.d. across r is 0 hence r in not needed to be consider

Thanks a lot

 

[Snowysangel]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s12_qp_21.pdf
Q3 b complete and
Q5 b complete

Mass will move with the greatest speed at the mean positio so 1 is either .2 or .6
It had greatest elastic potebtial energy when the gravational energy is the least so 2 is 0/0.8
3 is again 0.2/0.6
Are these answers righ?

 

[MiniSacBall]

Yeah, I generally keep my answer in 3 s.f, whether they ask ask for s.f or not
And in many of the m.s answers are in 3s.f

I have been saying this guy the exact same thing for like hours, he is so worried about s.f.

Will the examiners cut marks for our answers s.f. not being the same as m.s s.f.?

And it was 50 50 for me some questions in papers are to 2 others are to 3 sometimes within the same question different parts!!!

So now this is from CIE SALLAYBUS:

Mathematical requirements:
take account of accuracy in numerical work and handle calculations so that significant figures are
neither lost unnecessarily nor carried beyond what is justified.

For Practical Assessment only:
Table of results: calculated quantities
Candidates should be able to:
• calculate other quantities from their raw data
• use the correct number of significant figures for these calculated quantities.
Except where they are produced by addition or subtraction, calculated quantities should be given to
the same number of significant figures (or one more than) the measured quantity of least accuracy.
For example, if values of a potential difference and of a current are measured to 2 and 4 significant
figures respectively, then the corresponding resistance should be given to 2 or 3 significant figures,
but not 1 or 4. The number of significant figures may, if necessary, vary down a column of values for
a calculated quantity.
If you want go check for your self! here: http://papers.xtremepapers.com/CIE/...A and AS Level/Physics (9702)/9702_y14_sy.pdf
Are you ok now. Calm down!

 

[Thought blocker]

I have been saying this guy the exact same thing for like hours, he is so worried about s.f.


So now this is from CIE SALLAYBUS:

Mathematical requirements:
take account of accuracy in numerical work and handle calculations so that significant figures are
neither lost unnecessarily nor carried beyond what is justified.

For Practical Assessment only:
Table of results: calculated quantities
Candidates should be able to:
• calculate other quantities from their raw data
• use the correct number of significant figures for these calculated quantities.
Except where they are produced by addition or subtraction, calculated quantities should be given to
the same number of significant figures (or one more than) the measured quantity of least accuracy.
For example, if values of a potential difference and of a current are measured to 2 and 4 significant
figures respectively, then the corresponding resistance should be given to 2 or 3 significant figures,
but not 1 or 4. The number of significant figures may, if necessary, vary down a column of values for
a calculated quantity.
If you want go check for your self! here: http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_y14_sy.pdf
Are you ok now. Calm down!

Yaar, it's obvious if he can't get satisfactory answer, it's not his fault Now he will see by himself, and will be sure

 

[student1415]

Where is 6V ?

sorry it was 5 V in the marking scheme i didnt get tht

 

[Browny]

Then if the data is to 2.s.f then we must leave the ans to 2.s.f.

 

[Thought blocker]

sorry it was 5 V in the marking scheme i didnt get tht

Okay So you have two Voltages That are 225 and 230 yes ? (Keep 230 as V1 and 225 as V2)
So you need total Voltage in cell would be V = V1-V2 = 5V

 

[Thought blocker]

Then if the data is to 2.s.f then we must leave the ans to 2.s.f.

Do what question says

 

[student1415]

Okay So you have two Voltages That are 225 and 230 yes ? (Keep 230 as V1 and 225 as V2)
So you need total Voltage in cell would be V = V1-V2 = 5V

thank you soo much !! haha tht was simple

 

[Browny]

Do what question says

Some questions the data is to 2.s.f and if we can't state the answer to a greater number than justified then it should be to right?

 

[Asad Moosvi]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_22.pdf

In the first question, the last part, how do we know the time it reaches terminal velocity at?

 

[Browny]

Ah one more thing thought blocker there was a question where the answer was 4.533333333.......*10^-3 the ans in m.s was to 2s.f. that is 4.5*10^-3.

 

[Asad Moosvi]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_22.pdf

In the first question, the last part, how do we know the time it reaches terminal velocity at?

Anyone??

 

[Thought blocker]

Ah one more thing thought blocker there was a question where the answer was 4.533333333.......*10^-3 the ans in m.s was to 2s.f. that is 4.5*10^-3.

Hm, yeah, so what's the big deal ?

 

[forever_chocoholic]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w02_qp_2.pdf
can someone explain how to solve question 5 (b) please !!!!

 

[_Ahmad]

Anyone??

It reaches terminal velocity after falling about 10m
so we can find how long it takes to fall 10m from the equation s=ut+0.5gt^2
s=10m
ut=0 since initial velocity is zero
g=9.81
therefore t is about 1.43 s
so it reaches terminal velocity(7ms^-1) at about 1.43 s

 

[forever_chocoholic]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w13_ms_23.pdf
can anyone help me with question 5 c? pleaseeeeeeeeeeee

 

[mehria]

Anyone??

the terminal velocity is given in part c(ii) 1 n the distance is also given so we will simply find the time by any kinematics equation...

 

[Asad Moosvi]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_22.pdf

May someone please explain the last part of question 5? part b.

 

[DeViL gURl B)]

Th

Projectile Motion
Important Equations

Thank you soooooo much!!!!!