AdamRuby
Badges: 3
Rep:
?
#1241
Report 6 years ago
#1241
Is there a chance a six marker might come up on something to do with the thermal side of this unit? I really hope not...
0
reply
ThatRandomGuy
Badges: 1
Rep:
?
#1242
Report 6 years ago
#1242
(Original post by Jack93o)
mass is always less than it was before for fission and fusion
So for fission the new nuclei have less mass than the original?
0
reply
c.j.w
Badges: 0
Rep:
?
#1243
Report 6 years ago
#1243
(Original post by D4rth)
Are you sure about the data sheet? It might be outdated. The newest data sheet says 931.3

Posted from TSR Mobile
Maybe it is then, I'm sure the one I'm given in the exam is the same, but I wouldn't put it past my school to give me the wrong one. I'll just use 931.3 then to be sure, thanks!
0
reply
Thr33
Badges: 0
Rep:
?
#1244
Report 6 years ago
#1244
(Original post by ThatRandomGuy)
So for fission the new nuclei have less mass than the original?
Yes. Hence you get energy out. E = mc^2 and all that.
0
reply
bebubebubebu
Badges: 0
Rep:
?
#1245
Report 6 years ago
#1245
http://www.cyberphysics.co.uk/Q&A/KS...ivity/Q13.html
2
reply
UnknownOrigin
Badges: 0
Rep:
?
#1246
Report 6 years ago
#1246
(Original post by Jack93o)
they would never go something that specific for a 6 marker (i hope)
Maybe.

Or: explain how a CCD works and explain its advantages over photographic film
0
reply
sports_crazy
Badges: 0
Rep:
?
#1247
Report 6 years ago
#1247
(Original post by Jack93o)
mass is always less than it was before for fission and fusion

yeah, increase in binding energy leads to decrease in mass
How can fusion result in decrease in mass. I am confused . Wont it increase like from 2 hydrogen to helium.
0
reply
Jack93o
Badges: 14
Rep:
?
#1248
Report 6 years ago
#1248
(Original post by ThatRandomGuy)
So for fission the new nuclei have less mass than the original?
yeah
0
reply
Jack93o
Badges: 14
Rep:
?
#1249
Report 6 years ago
#1249
(Original post by UnknownOrigin)
Maybe.

Or: explain how a CCD works and explain its advantages over photographic film
:lolwut: what sort of advanatges are there over photographic film?

I know about the massively increased quantum efficiency with CCD, but what else?

I'd be ****ed if that question came up
0
reply
TeddyBasherz
Badges: 0
Rep:
?
#1250
Report 6 years ago
#1250
(Original post by UnknownOrigin)
Maybe.

Or: explain how a CCD works and explain its advantages over photographic film
Is the advantage that, for a CCD, the quantum efficiency is much greater than that for photographic film, which is around 4% compared to a CCD with 70-80%?
0
reply
anuradha_d
Badges: 1
Rep:
?
#1251
Report 6 years ago
#1251
Hey everyone

I dont understand how question 3 in June 2012 was answered... any help please?
0
reply
TeddyBasherz
Badges: 0
Rep:
?
#1252
Report 6 years ago
#1252
(Original post by sports_crazy)
How can fusion result in decrease in mass. I am confused . Wont it increase like from 2 hydrogen to helium.
As in there is a mass defect. The total mass of the two old nuclei combined will be slightly more than the larger, more stable nucleus created. This change in mass leads to energy given out to the surroundings (equivalent to E=(delta)mc^2).
0
reply
laser174572
Badges: 1
Rep:
?
#1253
Report 6 years ago
#1253
Anyone doing turning points know whether the tip of an STM is positively or negatively charged? The textbook says negatively but I'm not convinced because surely it has to be positively charged so as it attracts the tunnelling electrons?


Posted from TSR Mobile
0
reply
Jack93o
Badges: 14
Rep:
?
#1254
Report 6 years ago
#1254
(Original post by sports_crazy)
How can fusion result in decrease in mass. I am confused . Wont it increase like from 2 hydrogen to helium.
what I meant, is that the combined nucleus would have less mass than the two individual nuclei which were fused together

e.g.

each of those nuclei has a mass of 1kg

now, you'd expect the combined nucleus to be 2kg (1kg + 1kg)

BUT that doesn't actually happens

the combined nucleus would lose some of the mass, leaving it with say 1.9kg

the reason it loses mass, is because the nucleons (protons and neutrons) in the two nuclei lose potential energy

energy = mc^2

so if you lose energy, you also lose mass

apparently the same effect can be seen with boiled water, if you weigh a cup of 100 degree Celsius water, it would weigh more than the same cup of water at room temperature for example (but the difference in mass is very very slim)
0
reply
Jack93o
Badges: 14
Rep:
?
#1255
Report 6 years ago
#1255
(Original post by TeddyBasherz)
Is the advantage that, for a CCD, the quantum efficiency is much greater than that for photographic film, which is around 4% compared to a CCD with 70-80%?
thats the only thing I could think of, maybe you could add that CCD is digital, so it could be more readily used for data analysis or some crap like that, but yeah, thats a nasty question
0
reply
posthumus
Badges: 20
Rep:
?
#1256
Report 6 years ago
#1256
(Original post by laser174572)
Anyone doing turning points know whether the tip of an STM is positively or negatively charged? The textbook says negatively but I'm not convinced because surely it has to be positively charged so as it attracts the tunnelling electrons?


Posted from TSR Mobile
Probably negatively charged due to the electrons.... the electrons are accelerated via a positive anode in an electric gun and then this accelerates through the microscope
0
reply
bebubebubebu
Badges: 0
Rep:
?
#1257
Report 6 years ago
#1257
(Original post by anuradha_d)
Hey everyone

I dont understand how question 3 in June 2012 was answered... any help please?
read this, it really helps me
http://www.cyberphysics.co.uk/Q&A/KS...ivity/Q13.html
1
reply
laser174572
Badges: 1
Rep:
?
#1258
Report 6 years ago
#1258
(Original post by posthumus)
Probably negatively charged due to the electrons.... the electrons are accelerated via a positive anode in an electric gun and then this accelerates through the microscope
Don't the electrons quantum tunnel from the sample to the tip? I thought the one with an electron gun was transmission electron microscopy, not scanning?


Posted from TSR Mobile
0
reply
posthumus
Badges: 20
Rep:
?
#1259
Report 6 years ago
#1259
(Original post by laser174572)
Don't the electrons quantum tunnel from the sample to the tip? I thought the one with an electron gun was transmission electron microscopy, not scanning?


Posted from TSR Mobile
Okay sorry don't listen to me I still need to read this stuff... I'm only assuming!

& there's turning points thread here I made: http://www.thestudentroom.co.uk/show...2382437&page=4

Just easier to get to people who have turning points related questions
0
reply
UnknownOrigin
Badges: 0
Rep:
?
#1260
Report 6 years ago
#1260
(Original post by Jack93o)
:lolwut: what sort of advanatges are there over photographic film?

I know about the massively increased quantum efficiency with CCD, but what else?

I'd be ****ed if that question came up
-Increased quantum efficiency
-Its digital - so it can be easily processed by computers/programmes
-Can detect wavelengths beyond visible light region - so astronomers benefit as they can explore more
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • University of East Anglia
    Undergraduate Open Day Undergraduate
    Sun, 20 Oct '19
  • University for the Creative Arts
    Undergraduate Open Day Undergraduate
    Sun, 20 Oct '19
  • University of Gloucestershire
    Undergraduate Open Day Undergraduate
    Sun, 20 Oct '19

Have you made up your mind on your five uni choices?

Yes I know where I'm applying (56)
66.67%
No I haven't decided yet (18)
21.43%
Yes but I might change my mind (10)
11.9%

Watched Threads

View All