Physics P5, HELP!

[Twinkle Charms]

no problem
are you going to sleep soon? i'm doing nov 09 atm. i'll do june 08 and help you when i'm done if you're still here and if no one else has

its ok do post it anytime , ill chk late nyt or early morning, buh pleasee do explain also how do we decide on which is dependant and independant variable in any question?  particularly this ques =\

[girl_92]

im sooooo confused how do u find this erroe thing this log and all tht plz sum1 reply

[Twinkle Charms]

im sooooo confused how do u find this erroe thing this log and all tht plz sum1 reply

its oredy expalined in the first page, check that.

[falafail]

libra_92, check the previous page -_-

its ok do post it anytime , ill chk late nyt or early morning, buh pleasee do explain also how do we decide on which is dependant and independant variable in any question?  particularly this ques =\

well generally the independent variable is the one you vary, and dependent is the one whose value DEPENDS on the independent variable.
like for example if you have V=IR, with constant I
varying R, will change the value of V
so R is the independent value and V is dependent

[aorta]

ok my doubt jun08 (paper attached)
how do we know which is the dependant and independant variable?? =\

It says in the question that the student is given sheets of glass of different areas.

'Independent variable' is something that you can vary, which the 'dependent variable' depends on..

So here, you can varying the the area of the glass will have an effect on the resistance, therefor R depends on A.

So R is the dependent.. and  A the independent..

Hope you understood what I mean

[Twinkle Charms]

It says in the question that the student is given sheets of glass of different areas.

'Independent variable' is something that you can vary, which the 'dependent variable' depends on..

So here, you can varying the the area of the glass will have an effect on the resistance, therefor R depends on A.

So R is the dependent.. and  A the independent..

Hope you understood what I mean

so why dont we consider the lenght?

[aorta]

so why dont we consider the lenght?

Hmm, I'm not really sure. Maybe because in the question, it says we are given sheets of glass of different areas and same thickness. So I guess we should just assume that they have already varied the length and got different areas.

I think that it's pretty much the same thing.

Actually, lets say that you are the student, you are given 5 glasses of different areas, and each glass has it's area written on it. So you'll just use the different areas, why bother to vary the length and then get a different area when it's already done for you.

So you just use them..  I think.

[aorta]

Okay, M/J 2008, question 2 part a. How do you find the gradient and y-intercept??

I almost never get them right!

[nancy]

guys it says- USE RHEOSTAT to keep current constant?

how do you do that???

[falafail]

Okay, M/J 2008, question 2 part a. How do you find the gradient and y-intercept??

I almost never get them right!

rearrange the equation to give you y = mx + c
here you get ln R = ln Ro - pnx ln e
ln e = 1
so ln R = -pn x  + ln Ro
-pn is the gradient and ln Ro is the y-intercept

guys it says- USE RHEOSTAT to keep current constant?

how do you do that???

yeah i don't get that either :/


Zara, i tried doing that question but i really don't get it  
i know you have to plot R against 1/A though, and pl is the gradient, and that was your question right?
woops my bad, that wasn't your question. well since you're varying A to get different values of R, then A is the independent variable and R is the dependent variable.
but could anyone tell me how exactly we're supposed to set this experiment up? i'm okay with the analysis and safety precautions and whatnot, just the actual experiment is like o.O

[Twinkle Charms]

Zara, i tried doing that question but i really don't get it  
i know you have to plot R against 1/A though, and pl is the gradient, and that was your question right?
woops my bad, that wasn't your question. well since you're varying A to get different values of R, then A is the independent variable and R is the dependent variable.
but could anyone tell me how exactly we're supposed to set this experiment up? i'm okay with the analysis and safety precautions and whatnot, just the actual experiment is like o.O

so right, i dunno tht myself, my question was about the dep/indep variables,>>solved, buh how to set up no idea =\

anyways i think we gotta give it a break, its 2 37 am here, i give up hope n goin to sleep, just hope and pray whatever comes we're able to face it -.-

[falafail]

so right, i dunno tht myself, my question was about the dep/indep variables,>>solved, buh how to set up no idea =\

anyways i think we gotta give it a break, its 2 37 am here, i give up hope n goin to sleep, just hope and pray whatever comes we're able to face it -.-

hah yeah, hopefully we won't get anything about circuits or operational amplifiers. i absolutely HATE those stuff 
i'm gonna go through june and nov 07 before going to bed.
goodnight & goodluck

[Hwa1]

operational amplifiers?!
*heart attack*

[falafail]

operational amplifiers?!
*heart attack*

yeah.. someone posted this booklet with some experiments in it.. and one was about operational amplifiers.. i was like

[Hwa1]

anybody got a link to said booklet?