You are Here: Home >< Physics

# Unit 5 Physics Edexcel A2 and Edexcel IAL Watch

1. Fusion and Fission leads to an increase in Binding energy per nucleon.
Why is there an overall loss of mass if avg dinding energy per nucleon increases?

Posted from TSR Mobile
2. Any thread available for Unit 4 Physics? Need one badly for it
3. (Original post by physicsmaths)
Fusion and Fission leads to an increase in Binding energy per nucleon.
Why is there an overall loss of mass if avg dinding energy per nucleon increases?
I'm not sure if this is totally accurate so please somebody correct me if I'm wrong. I think binding energy per nucleon is basically a way of expressing the energy needed to break apart the nucleons. Since this is effectively a measure of the 'lack' of energy and e=mc^2, higher binding energy per nucleon = lower mass.
4. (Original post by sabahshahed294)
Any thread available for Unit 4 Physics? Need one badly for it
http://www.thestudentroom.co.uk/show....php?t=4030039
5. Thanks a lot!
6. If anyone is interested I managed to grab an AS textbook from my teacher and the wavelengths Edexcel considers "correct" are:

Microwave 10^5 - 10^-3
Infrared 10^-3 - 10^-5
Visible 10^-3 - 10^-7
UV 10^-6 - 10^-9
X-Ray 10^-7 - 10^-12
Gamma 10^-9 - 10^-16
7. (Original post by 16characterlimit)
If anyone is interested I managed to grab an AS textbook from my teacher and the wavelengths Edexcel considers "correct" are:

Microwave 10^5 - 10^-3
Infrared 10^-3 - 10^-5
Visible 10^-3 - 10^-7
UV 10^-6 - 10^-9
X-Ray 10^-7 - 10^-12
Gamma 10^-9 - 10^-16
Cheers

Posted from TSR Mobile
8. Anyone got some good revision notes? I've been constantly pushing back revising for this exam cause it is my very last, and I need to start changing that, just so much to know.
9. (Original post by 16characterlimit)
Anyone got some good revision notes? I've been constantly pushing back revising for this exam cause it is my very last, and I need to start changing that, just so much to know.
I've been concentrating on my other exams too - got to really work on unit 5 this week! Personally, I don't find revision guides very useful so I revise by going over the past papers again and again, but some people like the edexcel revision guide, I think.

http://www.physicsandmathstutor.com has some useful notes too.
10. Does anyone know if I can get by with saying 1 light year is 3x10^8 * 60*60*24*365.25 ?

And 1 AU is 3x10^8 * 60 * 8

Or do I have to remember them.
And does anyone know a good way of remember parsec to light year conversion, 3.26 right?
11. (Original post by 16characterlimit)
Does anyone know if I can get by with saying 1 light year is 3x10^8 * 60*60*24*365.25 ?

And 1 AU is 3x10^8 * 60 * 8

Or do I have to remember them.
And does anyone know a good way of remember parsec to light year conversion, 3.26 right?
Are you talking about if they ask for a definition for light year and 1 AU?

Na, I just do it the long way around. I calculate the distance for the parsec in m and then work out how many light years.
12. (Original post by PhysicsIP2016)
Are you talking about if they ask for a definition for light year and 1 AU?

Na, I just do it the long way around. I calculate the distance for the parsec in m and then work out how many light years.
I mean as if I need to do calculations requiring them, can I just work them out, or is that too rough to get an accurate answer.
13. (Original post by 16characterlimit)
I mean as if I need to do calculations requiring them, can I just work them out, or is that too rough to get an accurate answer.
Oh no that's exactly how I would do it tbh! I thought that 1 AU was given in the formula book anyway?
14. (Original post by PhysicsIP2016)
Oh no that's exactly how I would do it tbh! I thought that 1 AU was given in the formula book anyway?
Nope no constants for astrophysics for some reason, unless you count the one in Wein's law.
15. (Original post by 16characterlimit)
Nope no constants for astrophysics for some reason, unless you count the one in Wein's law.
Oh damn I was relying on that being in there (could've sworn it was haha)! I suppose in that case that's probably the best way of doing it then I sometimes remember it as 150 million kilometres but it's probably best to have a way of working it out too.
16. (Original post by 16characterlimit)
If anyone is interested I managed to grab an AS textbook from my teacher and the wavelengths Edexcel considers "correct" are:

Microwave 10^5 - 10^-3
Infrared 10^-3 - 10^-5
Visible 10^-3 - 10^-7
UV 10^-6 - 10^-9
X-Ray 10^-7 - 10^-12
Gamma 10^-9 - 10^-16
Thanks but how is it possible that a bunch of them overlap?
17. (Original post by Student403)
Thanks but how is it possible that a bunch of them overlap?
I guess it's something to do with the difference between consecutive wavelengths. Like if the difference between them is too small, then it can be quite difficult to differentiate which type of EM radiation is it.
18. Can anyone explain what June 2012, Question 19iv is about?
Paper: http://qualifications.pearson.com/co...e_20120618.pdf
Mark Scheme: http://qualifications.pearson.com/co...s_20120816.pdf
19. (Original post by sabahshahed294)
I guess it's something to do with the difference between consecutive wavelengths. Like if the difference between them is too small, then it can be quite difficult to differentiate which type of EM radiation is it.
But that would imply multiple answers are correct for a given wavelength? I've seen 2 of those questions so far asking to name the category, and only 1 is accepted
20. (Original post by Student403)
But that would imply multiple answers are correct for a given wavelength? I've seen 2 of those questions so far asking to name the category, and only 1 is accepted
As I said, I just took a guess that this "might" be the reason behind the overlapping. Because I also feel a bit confused about it myself.(When I think in terms of the MCQs because if we considered overlapping, then we would have more than one possible answer and that's not possible!)

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: June 29, 2016
Today on TSR

### What is the latest you've left an assignment

And actually passed?

### Simply having a wonderful Christmas time...

Discussions on TSR

• Latest
• ## 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.

• Poll
Useful resources

Can you help? Study help unanswered threadsStudy Help rules and posting guidelinesLaTex guide for writing equations on TSR

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## 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.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.