Physics, Chemistry and Biology: Post your doubts here!

[mrnt3250]

thankuu

You're welcome.
I'm leaving for the paper 32 physics, I hope I will not run out of time.
All the best.

 

[sma786]

You're welcome.
I'm leaving for the paper 32 physics, I hope I will not run out of time.
All the best.

kool , my paper 31 is 8 hours later
best of luck =)

 

[aliiiiiiiiii]

who's done with the physics ??!! i hope its easy

 

[EpicLol]

Could someone plz explain what and how the ropes/springs and strain and tension work?
Thx....

 

[EpicLol]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s07_qp_3.pdf
last question , (b) ? how to :\

Because the particles, most of them go though, some get deflected a little and some get completely reversed, this tells us that there is something bigger than the particles inside the foil which is causing them to be reversed and this could not be the electrons most of them pass through as an atom is mostly empty space, the ones that collide with the nucleus are the ones that get deflected backwards and in random directions......you will need to shorten this for the exam....
Its Rutherford's gold foil experiment

 

[EpicLol]

who's done with the physics ??!! i hope its easy

are you done with your physics? Was it hard?

 

[aliiiiiiiiii]

are you done with your physics? Was it hard?

wel am done eccept see oct 08 31 q1 d ii
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w08_qp_03.pdf

 

[aliiiiiiiiii]

are you done with your physics? Was it hard?

oh no am doing after 8 hrs

 

[aliiiiiiiiii]

wel am done eccept see oct 08 31 q1 d ii
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w08_qp_03.pdf

any 1

 

[EpicLol]

wel am done eccept see oct 08 31 q1 d ii
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w08_qp_03.pdf

0.5 m/s^2 is acceleration due to 0.4N weight.....so to get m we multiply by s and then by s again, then we divide by 2 to get the answer as its 0.5m/s^2 and not 1m/s^2

 

[Muzammil100]

any 1

In the table 0.4 N has acc 0.50 m/s^2 after 0.25 m/s^2
but in the question its starting from rest so it will have 0.25 m/s^2

 

[aliiiiiiiiii]

ho

0.5 m/s^2 is acceleration due to 0.4N weight.....so to get m we multiply by s and then by s again, then we divide by 2 to get the answer as its 0.5m/s^2 and not 1m/s^2

w

 

[aliiiiiiiiii]

In the table 0.4 N has acc 0.50 m/s^2 after 0.25 m/s^2
but in the question its starting from rest so it will have 0.25 m/s^2

how

 

[ThatReallyReallyWeirdDude]

v=u+at?
u= initial speed, acceleration = a=0.5 t=1.2
v=0 + 0.5(1.2) =0.6m/s
ii) Distance
can use average speed (s= [v+u]/2 * t]
which gives distance = 0.3*1.2=0.36
or s=ut+1/2at^2
=0+(0.5)(0.5)(1.2)^2=0.25*1.44=0.36

 

[Muzammil100]

v=u+at?
u= initial speed, acceleration = a=0.5 t=1.2
v=0 + 0.5(1.2) =0.6m/s
ii) Distance
can use average speed (s= [v+u]/2 * t]
which gives distance = 0.3*1.2=0.36
or s=ut+1/2at^2
=0+(0.5)(0.5)(1.2)^2=0.25*1.44=0.36

You seem to be really good in Physics!

Mashallah!

 

[tribianni]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s04_qp_3.pdf Q 4b helpieeeeeeee

 

[ZainH]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s04_qp_3.pdfQ 4b helpieeeeeeee

Specifc latent hate formula is
Latent heat= energy/mass
So, just put in the values.

34500-600/15g

We substract 600 as it was lost to the surroundings.
Your answer is, 2260j/g

 

[ThatReallyReallyWeirdDude]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s04_qp_3.pdf Q 4b helpieeeeeeee

You seem to be really good in Physics!

Mashallah!

Thank you! Inshallah we'll both get A*

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s04_qp_3.pdf Q 4b helpieeeeeeee

Molecules which have higher kinetic energy have a higher chance to break their bonds and escape (evaporation). At 85*C more energetic molecules exist and thus more water has evaporated/more molecules have broken their bonds which is why the level is lower.
b)Okay it said that 600j was lost to atmosphere so only 34500-600=33900J was used to melt 15g of water
Energy = Mass * latent Heat of Fusion
Latent Heat of Fusion = Energy/Mass = 33900/15=2260J/g

 

[ThatReallyReallyWeirdDude]

Zain beat me!
So anyone know how to calibrate a C.R.O?
When they ask to calibrate a C.R.O. i assume it means find the Y-Gain/Time Base?
So that would mean you'd put in a source of known voltage on the Y-inputs (with X-Inputs being an A.C. source)
Measure the amplitude of resultant wave
and Y-Gain would be input voltage/amplitude (since we know the voltage input)
And then if we know the frequency of the input we can use that to find the time base
THAT'S assuming that that's what the question wants from us.

 

[ZainH]

Zain beat me!
So anyone know how to calibrate a C.R.O?
When they ask to calibrate a C.R.O. i assume it means find the Y-Gain/Time Base?
So that would mean you'd put in a source of known voltage on the Y-inputs (with X-Inputs being an A.C. source)
Measure the amplitude of resultant wave
and Y-Gain would be input voltage/amplitude (since we know the voltage input)
And then if we know the frequency of the input we can use that to find the time base
THAT'S assuming that that's what the question wants from us.

Never learned how to calibrate a C.R.O , only thermometers .
If thats a question from a past paper in around 2000-2005, the syllabus was a little different back then.