Biology; Chemistry; Physics: Post your doubts here!

[Suchal Riaz]

hey i didnt get the answer of the indentification of X and Y plzzzzzzz help?

which question? please repeat it so that i can explain you.

 

[CoolBreeze]

What it means is that u have to actually know the meaning of those words at the end like thinking distance braking distance etc .....
then u have to actually be able to solve the effects on the friction of a moving vehicle like the effect of increasing thinking distance or breaking distance then what happens also effects which reduce friction like tyre surface whether it can grip well like when its worn out or when the road is slippery etc. so u have to be able to interpret the effects of this on friction thats all !




Well since u increased the force to 20N and the old force was 10N where the object was moving with constant speed therefore the frictional force is 10N so using Newtons Second law :
20-10=2a
a=5 m/s^2



Cant do Q 1 because u havent specified correctly what u want to compare MgO with !

Q2 is an A Level question surprised you are doing these when in A Levels (if u still need the answer then tell me )

Q3 is basically the reaction of Nitrogen with Oxygen as u know that N2 is inert in the atmosphere because the reaction with O2 requires lots of heat and is endothermic it takes place during lightning !
therefore V and W are oxygen and Nitrogen respectively they at first form NO then as NO reacts with more V they form NO2 the brown gas ! which then reacts with oxygen and water to form Nitric acid ! the constituent of acid rain !

For the reaction of Al with Hcl use the equation below
2Al + 6HCl ----> 2AlCl3 + 3H2
Now work your way through by using 100cm^3 of H2,find the moles of H2 then use ratio and get Al moles and then find its mass using its Atomic mass !

Q4 again wont advise you to do them but tell me where u got these questions i wonder if u are doing IGCSE ! do tell ?

so wht is the difrnc b/w braking and stopping distance???

 

[scouserlfc]

so wht is the difrnc b/w braking and stopping distance???

Basically Stopping distance is equal to the braking distance + Thinking distance this is not a formula but its definition its the total distance traveled while the braking is in progress!
While braking distance is the distance the car travels while the brakes are applied !

 

[CoolBreeze]

Basically Stopping distance is equal to the braking distance + Thinking distance this is not a formula but its definition its the total distance traveled while the braking is in progress!
While braking distance is the distance the car travels while the brakes are applied !

Thank you!!!

 

[zainabkhann]

Hey guys, hope everyone did well on their exams. I would like to clarify one thing. I will be giving olevel physics exam in the next upcoming session for 2013. I have checked the dates, and paper 1 and paper 2 are on the same date on the same morning session. Can this be possible? has someone else encountered this when giving exams? do u first give paper 1 , rest for a bit and then do paper 2? or is there no break given between these two exams? please help me to understand this. Thanks

 

[Arsallan Sarwar]

Hey guys............... I need all the material which can get me higher grades in Physics and Chemistry.

 

[Mars-on-Earth]

Hey guys, hope everyone did well on their exams. I would like to clarify one thing. I will be giving olevel physics exam in the next upcoming session for 2013. I have checked the dates, and paper 1 and paper 2 are on the same date on the same morning session. Can this be possible? has someone else encountered this when giving exams? do u first give paper 1 , rest for a bit and then do paper 2? or is there no break given between these two exams? please help me to understand this. Thanks

The papers are on the same date, yes. I'm giving mine then as well. Also for chemistry the schedule is same. All the people I've talked to say that there is a gap of 15 to 30minutes between the two papers. Don't worry, there won't be a mess of it. But you need to prepare beforehand to deal with the two papers. Schools give us that practice.

 

[Mars-on-Earth]

Can anyone please give me the link to the marking scheme of Physics 5054, June 2003 paper1? I cannot find it on xtremepapers, the site has marking schemes from 2004 onwards.

 

[scouserlfc]

Hey guys, hope everyone did well on their exams. I would like to clarify one thing. I will be giving olevel physics exam in the next upcoming session for 2013. I have checked the dates, and paper 1 and paper 2 are on the same date on the same morning session. Can this be possible? has someone else encountered this when giving exams? do u first give paper 1 , rest for a bit and then do paper 2? or is there no break given between these two exams? please help me to understand this. Thanks

No need to worry,you should actually be happy that you have both papers of the same subject and exactly at one time think of others who have to come in the PM session as well as AM and give two different subs so relax and yes i did face it for all Physics,Bio and Chem this same thing that you will face ! As soon as one of your paper ends they take your paper then you have another 10 minutes to relax then as soon as 10 minutes pass you are handed the next paper in this case P2 and u are told to write name etc. and as soon as 15 mins pass u start again its not anything u need to worry abt but try building ur stamina i ve seen some people fainting

 

[Suchal Riaz]

Can anyone please give me the link to the marking scheme of Physics 5054, June 2003 paper1? I cannot find it on xtremepapers, the site has marking schemes from 2004 onwards.

when the cie started publishing them from 2004, then how can any site give you markschemes before 2004?

 

[scouserlfc]

Can anyone please give me the link to the marking scheme of Physics 5054, June 2003 paper1? I cannot find it on xtremepapers, the site has marking schemes from 2004 onwards.

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s03_er.pdf

Here the er is the examiner report for P1 its exactly like Marking scheme and its better because it has comments on some question also for P2 and P4 its still okay as u get the idea whether ur answer is correct or not ! By the way the examiner report is an important piece of paper make sure u read it after u solve each year its of massive help

 

[scouserlfc]

when the cie started publishing them from 2004, then how can any site give you markschemes before 2003?

Actually we do have er and i think ms were also there but since they added 2012 papers and there has to be some limit to the storage of these papers so they actually remove the old papers but still er is there

 

[Mars-on-Earth]

when the cie started publishing them from 2004, then how can any site give you markschemes before 2004?

Didn't know that... -_-

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s03_er.pdf

Here the er is the examiner report for P1 its exactly like Marking scheme and its better because it has comments on some question also for P2 and P4 its still okay as u get the idea whether ur answer is correct or not ! By the way the examiner report is an important piece of
paper make sure u read it after u solve each year its of massive help

Thankyou

 

[CoolBreeze]

Explain 4 e).... What does it mean????

 

[papajohn]

Explain 4 e).... What does it mean????
View attachment 20546

On earth
Mass = 100 Kg
Weight = 1000N
On Moon
Mass = 100Kg weight =200N
This is because of the gravity.So that is the very simple concept.

 

[CoolBreeze]

On earth
Mass = 100 Kg
Weight = 1000N
On Moon
Mass = 100Kg weight =200N
This is because of the gravity.So that is the very simple concept.

Maybe u shd read the point again!!!
I really don't understand how u r taking it!!!!
Explain that weight therefore masses may be compared using a balance!!!

 

[papajohn]

 

[zainabkhann]

No need to worry,you should actually be happy that you have both papers of the same subject and exactly at one time think of others who have to come in the PM session as well as AM and give two different subs so relax and yes i did face it for all Physics,Bio and Chem this same thing that you will face ! As soon as one of your paper ends they take your paper then you have another 10 minutes to relax then as soon as 10 minutes pass you are handed the next paper in this case P2 and u are told to write name etc. and as soon as 15 mins pass u start again its not anything u need to worry abt but try building ur stamina i ve seen some people fainting

haha thankyou so much for the descriptive answer first of all, now i know exactly what to do to train myself for exam conditions. but i would rather come again some other day after revising for that specific paper, instead of studying for both, even though it does have some benefits, like all you studying is applied and utilized at the same time in one day, but still.

 

[Suchal Riaz]

Explain 4 e).... What does it mean????
View attachment 20546

on a balance, mass is measured sue to it's weight
on balance there are masses in two sides and one is raised until it matches the other one so we know how much other thing weighs.
It wouldn't be difficult for you if you have seen old kind of balance for measuring mass or weight.

 

[Tayyaba]

Heyy
I really need a good biology tutor for O levels who can help me get through with the upcoming exams in May.
Or can someone please tell me if there's a good academy that I can join?

p.s I'm from Lahore..