Physics 43!! How was it?? Expected GT anyone?

[Kandinsky]

Anyway, recall the first task, where you should find the binding energy of uranium. how would you solve that without knowing masses of proton and neutron (which were given). The table contained the 3 headings: particle/ mass and binding energy per nucleon. Data for every particle and nuclei was given. The masses as well, so I don't see any evidence that my approach is incorrect.

 

[Kandinsky]

No. I didn't round it up to 200. I got something like 199.89 etc. It is because the neutrons were also the products of the reaction.

 

[Kandinsky]

I don't remember my wavelength, but the others are the same

 

[Kandinsky]

all i did for that was find the mass of uranium using the proton and neutron valuses they gave, then found the mass defect, then put the mass defect into e=mc2 and i got 7.18Mev after i divided it by the charge of the electron

I am trying to say that the masses were given for all the nuclei and particles. don't you remember the voltage in de Broglie problem?

 

[Kandinsky]

ohhh, you do know that the neutrons dont contribute to the enrgy that is released, the have no binding enery, they are on bonded to anything else they are just free neutron, thats like one of the basic things

I don't know how to explain it to you. We had mass-energy before the reaction and after. All the lost mass is the energy released.

 

[Kandinsky]

The mass-energy is conserved. I don't say anything about neutrons. All the lost mass is the energy released.

 

[Kandinsky]

I messed up there. it's correct, if you use rms

 

[Henry930821]

something about 2.6v just came into my head or somfin like that

wasn't v.rms = 2.8v ? and what was the value of the final answer for resistance?

 

[Anonymous']

well for some of the other
i got 1.79 10-11 for the wavelenght
46.6 for the lenght of the cable for the last question
1330 for the rms

Yes! I got the same answers as yours! heheh

 

[Henry930821]

well for some of the other
i got 1.79 10-11 for the wavelenght
46.6 for the lenght of the cable for the last question
1330 for the rms

hey what was 1330 for? which question again? hmm

 

[Mattman]

wasn't v.rms = 2.8v ? and what was the value of the final answer for resistance?

Power i got 2.96x10^-3W, P=v square/R

the resistance is just a straight line

 

[Mattman]

Power i got 2.96x10^-3W, P=v square/R

the resistance is just a straight line

any1 know whats the advantages of modulated waves over normal waves?

 

[Henry930821]

Power i got 2.96x10^-3W, P=v square/R

the resistance is just a straight line

yeap i got this answer too =)

 

[dadufahad]

I find it difficult hope that the gt will be around 50 so that i might still stand a chance to get A
By the way, anyone here knows how exactly to convert the marks? I mean like I got 87 in AS level, so how many marks must I score for paper 4 and paper 5 to get an A?

i got exact 87 in biology..

 

[dadufahad]

DIFFICULT........especially the binding energy that question..anyone knows how to solve it?

i lost marks in that only..except that evrythin was easy..

 

[issac0215]

although you could have also worked back from the second question and got the first for that,

YEP , i did that..hahahahaha

 

[Mattman]

things along those lines

Lol I said less attenuation and noise, and higher bandwidth, since they ave sidebands. IIs it applicable?

 

[Mattman]

but then your working is gonna be diff from what you actually had to do, i wonder if that matters though

I did RHS-lhs but for some reason I didn't get the wanted answer for some reason, lol. I did write down the working, though

 

[Mattman]

is this forthe first two questions, because i never did and rhs -lhs, or any side for that matter

Oh ok what u did instead

 

[Mattman]

find the mass defect and put it into e=mc2, for uranium, but for the first one keep it in atomic mass units and you get 1.808u

I did the 2 larger nucleons plus 1 neutron and 7 electrons minus the uranium nucleus or something