Physics: Post your doubts here!

[geek101]

ms: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_ms_22.pdf
qp: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_22.pdf

in question 2bii, if you rearrange the equation you get that r and v are inversely proportional...so in the question if the radius is decreased the velocity is supposed to be more. someone please explain what the mark scheme says for this

 

[Peter Check]

in series: Vtotal=V1+V2+V3 .... Itotal=I1=I2=I3 .... Rtotal=R1+R2+R3..
In parallel: Vtotal=V1=V2=V3 .... Itotal=I1++I2+I3.... Rtotal= 1/R1+ 1/R2 + 1/R3 ...

For V total in parallel, what if one emf is 3V and the other is 10V?? Then how can Vtotal=3=10 ??

 

[gary221]

How do v do this???

Ans is 2...May/June 2009

 

[Shomail Arif]

Can someone please post a link to all the important formulass? Thankss

 

[geek101]

ms: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_ms_22.pdf
qp: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_22.pdf

in question 2bii, if you rearrange the equation you get that r and v are inversely proportional...so in the question if the radius is decreased the velocity is supposed to be more. someone please explain what the mark scheme says for this

 

[Goku]

Can someone please post a link to all the important formulass? Thankss

Here you go!

 

[leosco1995]

and wont you multiply that value by 1.4 after that? :O

Whoops. Fixed.

 

[gamer_boy]

Yes, I did! Thank you so much! Also, what is eVand MeV? I'm afraid I haven't ever come across these. http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_23.pdf Q.7(b)(i)

haha yeah eV i was also confused bout that, just learnt it today., well
whenever the question comes of eV , susbsitute the value of elementry charge in it i.e 1.60*10^-19
e.g , in june 2010 paper i dun remember the varient, it said, 5.4MeV , so for this, u have to
(5.4*10^6) * 1.60*10^-19
hope u got it, just u have to do is substitute the value of elementry charge in place of eV and the rest u knw for mega , mili watever given in the question , hope u got it.

 

[Peter Check]

ms: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_ms_22.pdf
qp: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_22.pdf

in question 2bii, if you rearrange the equation you get that r and v are inversely proportional...so in the question if the radius is decreased the velocity is supposed to be more. someone please explain what the mark scheme says for this

I didnt use the formula approcah, the acceleration of the second drop would be less than the acceleration of the first, so the second drop will have a lower slope.

 

[geek101]

I didnt use the formula approcah, the acceleration of the second drop would be less than the acceleration of the first, so the second drop will have a lower slope.

so you arnt supposed to use the formula

 

[Peter Check]

so you arnt supposed to use the formula

I dont think so, i had the same doubt http://www.xtremepapers.com/communi...-objects-shape-or-the-mass.16691/#post-292465

 

[Peter Check]

so you arnt supposed to use the formula

plus if you look carefully the question say "There is a frictional
force F acting on the sphere, which is given by the expression" which means the formula holds true for only that sphere, and not another one(of a diff radius)

 

[lavanyamane]

eV = electron volt, and MeV = mega electron volt.

e = magnitude of charge on electron = 1.6 x 10^-19. Units = C.
V = voltage. Units = J/C.

When they multiply, the units of C cancel out so you are left with J, meanings its a energy quantity. The M just means mega (10^6).

So if you want to calculate for example, the value of 1.4 MeV, then it would be:

1.4 * 10^6 * 1.6 * 10^-19 J.

Right, I understand! Thank you

 

[lavanyamane]

haha yeah eV i was also confused bout that, just learnt it today., well
whenever the question comes of eV , susbsitute the value of elementry charge in it i.e 1.60*10^-19
e.g , in june 2010 paper i dun remember the varient, it said, 5.4MeV , so for this, u have to
(5.4*10^6) * 1.60*10^-19
hope u got it, just u have to do is substitute the value of elementry charge in place of eV and the rest u knw for mega , mili watever given in the question , hope u got it.

Yes, absolutely! Thaaaank you

 

[gamer_boy]

Yes, absolutely! Thaaaank you

lolx np np

 

[gary221]

How do v do this???
View attachment 11482
Ans is 2...May/June 2009

Umm...guys??
A little help pls??

 

[geek101]

plus if you look carefully the question say "There is a frictional
force F acting on the sphere, which is given by the expression" which means the formula holds true for only that sphere, and not another one(of a diff radius)

but we know that a frictional force will act on the other raindrop too, its impossible that it doesnt....
i read the examiners report and i understand. thank you though!

 

[SalamH]

ppl how do you know how many sf the ans shud b given to coz markschemes says diff sf 4 diff ques

 

[geek101]

ms: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_ms_22.pdf
qp: http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_22.pdf

for 4a can someone please very very kindly give a picture of the apparatus to be used! THANK YOU!

 

[iKhaled]

Umm...guys??
A little help pls??

this question is the worst in the past papers, and i just don't know what is maxima and minima! pls someone explaiiiinnnnnnn!