Physics Unit 4 JUNE 11/6/12

[étudiante]

hey iru, 1 more thing
in question 14 c, in 2012 jan unit4, what am I expected to know?
http://www.thestudentroom.co.uk/attachment.php?attachmentid=141772&d=1334383807

mind posting the paper? cuz i dont have it

(the paper i did :') )

 

[Evolution]

lol, and yah I posted it

 

[étudiante]

lol, and yah I posted it

I saw it later sorry

the particle is moving in a circular path so the force is towards the center of the circle, the current is moving in the direction of the pi+ (i.e downwards) so u can easily find the field

 

[Evolution]

Thanks alot!!!
I missed the point that force is to the middle of the circle

 

[étudiante]

Thanks alot!!!
I missed the point that force is to the middle of the circle

ur welcome

most of the ppl left dis i remeber cuz of dat

 

[Evolution]

lol, I'm soooo sorry 2 more final thing, for question 9 in the same paper, what am I expected to know?
and question 2 as well.

 

[étudiante]

lol, I'm soooo sorry 2 more final thing, for question 9 in the same paper, what am I expected to know?
and question 2 as well.

no problem at all tho ur lucky cuz i was just abt to go when i saw ur alert

Q9) u need to know dat charge is conserved so only option B is possible (because it gives nett of +1 )

Q2) Option C i think cuz 3 and 4 are resultants of 1 and 2
(but m not sure, i was stuck on this MCQ in the exam too )

 

[Evolution]

thanks alot iru I'm off now, cya in a bit pray for me... thanks again!

 

[étudiante]

thanks alot iru I'm off now, cya in a bit pray for me... thanks again!

pleasure's all mine n sure i will dw never mention
byee!

 

[svenas]

when you have any of these things given, if you know where the emf, or motion, or field is, then use it. The left hand rule is force for the thumb, field for the index, and current for the middle.

Heyyy how was ur exam?? i guess the hardest que was for the electric field so can we discuss the paper if u don mind cuz i hve doubt for sme questions

 

[Evolution]

The exam was awesome alhamdolilah, but I may loose 5-15 marks, I didn't really know what to do with the questions where it said show that the equation is correct.

 

[svenas]

same here i just left them and 4 the momentum part too i left i couldnt draw the vector diagram how much u got for the Mev after drawing the vector diagram and was was the mass 4 the up quark?and i wil tel u sme of my answers whch i wrote nw 4 the MSQ the time constant i got 3.2 and whn they askd abt spacecraft my ans was -8.02... for the capacitor calculation we shld use the 400 hz ryt? and the most imp que i was confused of for the wavelength calculation i did it ths way E=mc2 so (2x9.11x10-31)x(3x108)2 then i used the E=hf formula is that correct? and im really sry for disturbing

 

[svenas]

same here i just left them and 4 the momentum part too i left i couldnt draw the vector diagram how much u got for the Mev after drawing the vector diagram and was was the mass 4 the up quark?and i wil tel u sme of my answers whch i wrote nw 4 the MSQ the time constant i got 3.2 and whn they askd abt spacecraft my ans was -8.02... for the capacitor calculation we shld use the 400 hz ryt? and the most imp que i was confused of for the wavelength calculation i did it ths way E=mc2 so (2x9.11x10-31)x(3x108)2 then i used the E=hf formula is that correct? and im really sry for disturbing

can u plz tel me if they r ryt cuz im affraid a lil bit if my ans will be wrng

 

[svenas]

The exam was awesome alhamdolilah, but I may loose 5-15 marks, I didn't really know what to do with the questions where it said show that the equation is correct.

same here i just left them and 4 the momentum part too i left i couldnt draw the vector diagram how much u got for the Mev after drawing the vector diagram and was was the mass 4 the up quark?and i wil tel u sme of my answers whch i wrote nw 4 the MSQ the time constant i got 3.2 and whn they askd abt spacecraft my ans was -8.02... for the capacitor calculation we shld use the 400 hz ryt? and the most imp que i was confused of for the wavelength calculation i did it ths way E=mc2 so (2x9.11x10-31)x(3x108)2 then i used the E=hf formula is that correct? and im really sry for disturbing

 

[Evolution]

umm, the vector diagram was easy, just draw the vectors with the same length, and angle. Then you connect the last part of the diagram with the origin, this connecting line is the unshown particle. You just need to measure it with a ruler to find it's Mev.
for the spacecraft You had to use the principle of conservation of momentum, the total momentum of the aircraft before loosing the mass is equal to the momentum of the spacecraft after loosing the mass - the momentum of the lost mass moving in the other way. (- sign is because the mass is moving in the opposite direction) this should give u about +8m/s
for the capacitor I also used the 400Hz.
For the wavelength it had 5 marks, so u had to do a little work.
First you say that the total energy of 1 electron= e which is something like 1.6x10^-19 I think.
So this energy will be equal to the kinetic energy of the ...ermm.. I don't really remember this question. Let me try to remember it and get back to u, and no not at all, your not annoying

 

[svenas]

umm, the vector diagram was easy, just draw the vectors with the same length, and angle. Then you connect the last part of the diagram with the origin, this connecting line is the unshown particle. You just need to measure it with a ruler to find it's Mev.
for the spacecraft You had to use the principle of conservation of momentum, the total momentum of the aircraft before loosing the mass is equal to the momentum of the spacecraft after loosing the mass - the momentum of the lost mass moving in the other way. (- sign is because the mass is moving in the opposite direction) this should give u about +8m/s
for the capacitor I also used the 400Hz.
For the wavelength it had 5 marks, so u had to do a little work.
First you say that the total energy of 1 electron= e which is something like 1.6x10^-19 I think.
So this energy will be equal to the kinetic energy of the ...ermm.. I don't really remember this question. Let me try to remember it and get back to u, and no not at all, your not annoying

hmm so am i goin to lose marks for the negative sign in momentum and i guess it was explosion momentun isn't it? i wrote the initial momentum was zero ? and 4 the wavelength i jst multiplied once bt 2 is tht correct i got around 2.1x10 smethng maybe i don remember well and whn they askd abt the up quark mass i jst wrote 2/3 mev/c2 and the reason why it tok long time to discover the up quark i wrote bcz it produces neutral particles which hve no effect wth magnetic and electric fields wat abt u?

 

[Evolution]

yea it is, and the negative sign will make u loose a mark. the initial momentum wasn't zero, it was the initial speed of the whole body x the whole mass of the body.
for the wavelength I remmember having to divide the energy by 2, since you wanted to find the energy of each photon, and there where 2 photons emitted. I don't think that mass was correct. And for the reason, if you look back in the question, it says that the 'TOP" quark (not the up by the way) is occassionaly produced when a proton and an antiproton collide, so it's rare to find it. Plus it's mass was realllyyy small, so it's hard to detect. These are 2 points, and the question had 2 marks.

 

[svenas]

yea it is, and the negative sign will make u loose a mark. the initial momentum wasn't zero, it was the initial speed of the whole body x the whole mass of the body.
for the wavelength I remmember having to divide the energy by 2, since you wanted to find the energy of each photon, and there where 2 photons emitted. I don't think that mass was correct. And for the reason, if you look back in the question, it says that the 'TOP" quark (not the up by the way) is occassionaly produced when a proton and an antiproton collide, so it's rare to find it. Plus it's mass was realllyyy small, so it's hard to detect. These are 2 points, and the question had 2 marks.

bt i get for the momentum que 8.02 and i thought its goin 2 be initial momentum is zero nw im depressed ok for the 1st que of the capacitor i hve 2 find the time of the 400 hz and the time constant for the capacitor ryt and then i wrote tht it wil take less time for the capacitor to discharge bcz its time is smaller is it ryt? then for its last part cuz i hadn't had enough time i wrote its consistent bcz the values r close 2 each other

 

[the golden girl]

Tht was such an amazing exam , just made me love the examiners even MORE =,=

 

[*Sandra*]

Inshallah

when is the exam btw?

hiii how r u ... hope u remember me actually i was using my bro's account *svenas* and jst 2day i made my own account cuz he's fedup wth me tht i always ask him 2 open it 4 me..anyways i need ur help for these 2 que's: Q1: What is the link between a radiation's ionising ability and its ability to penetrate material? and Q2: In what ways are the behaviours of a collection of dice and a sample of radioactive isotopes similar? Thanks in advance