Join TSR now and get all your revision questions answeredSign up now

AQA Physics PHYA5 - Thursday 18th June 2015 [Exam Discussion Thread] Watch

    Offline

    1
    ReputationRep:
    (Original post by superduperbob)
    I put main sequence
    -82 is definitely wrong if that's the absolute magnitude one, as it only goes down to -26
    Offline

    2
    ReputationRep:
    In the resolution question where lambda is between 1 and 5, which value of lambda were we supposed to use 1, 5 or 3?
    Offline

    2
    ReputationRep:
    (Original post by lad123)
    For the one you got 160,000 i thought you were supposed to square them first then add them, and then divide by 3?
    I initially thought this too. But I looked at the units, which were  m^2s^-^2
    So I calculated the mean. Then I just squared it all.
    Offline

    0
    ReputationRep:
    Guys did your paper for section b have R on the end of the code
    Offline

    1
    ReputationRep:
    (Original post by Lizzieee4)
    For that did you work out Q for Q=mcT and Q=ml and add them ?
    yes
    Offline

    1
    ReputationRep:
    (Original post by Lizzieee4)
    For that did you work out Q for Q=mcT and Q=ml and add them ?
    I did Q = mct + ml
    • Study Helper
    Offline

    3
    ReputationRep:
    (Original post by StarvingAutist)
    No, you add it. The largest distance is when the earth is on the opposite side of the sun compared to.. the thing
    Ahh ok seems I got that wrong then


    Posted from TSR Mobile
    Offline

    1
    (Original post by lad123)
    For the questions it said show that the value is 'about' x, such as show it was 1.4*10^-15 m and you get 1.43*10^-15, for the next part in the questions do you use 1.43 or 1.4? or doesn't it matter?
    they accept both answers
    Offline

    7
    ReputationRep:
    (Original post by superduperbob)
    I put main sequence
    I put main sequence as well in the end after changing from dwarf star, people at my school saying dwarf but I thought the power output was way too high to be a dwarf star
    Offline

    3
    ReputationRep:
    (Original post by StarvingAutist)
    No, you add it. The largest distance is when the earth is on the opposite side of the sun compared to.. the thing
    Yup!
    I added 1AU + 2.57AU (largest distance) to get something like 3.57AU to get the largest possible distance.

    Posted from TSR Mobile
    • Study Helper
    Offline

    3
    ReputationRep:
    (Original post by fruity97)
    I put main sequence as well in the end after changing from dwarf star, people at my school saying dwarf but I thought the power output was way too high to be a dwarf star
    I thought this aswell


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    Anyone get 2.07x10^6 m2s-2(might have been 7 cant remember) and get 4.7x10^4Jor around that?
    Offline

    2
    ReputationRep:
    (Original post by fruity97)
    I put main sequence as well in the end after changing from dwarf star, people at my school saying dwarf but I thought the power output was way too high to be a dwarf star
    i used the fact that its power output is similar to the sun, but much hotter
    Offline

    1
    ReputationRep:
    (Original post by SuperMushroom)
    I thought this aswell


    Posted from TSR Mobile
    I did it based on temp, it was 5,000K which is an orange star, so therefore it should be a main sequence star
    Offline

    2
    ReputationRep:
    (Original post by k9000)
    Anyone get 2.07x10^6 m2s-2(might have been 7 cant remember) and get 4.7x10^4Jor around that?
    I think I may have had 2.06x10^7 but otherwise yes I concur for both
    Offline

    3
    ReputationRep:
    (Original post by k9000)
    Anyone get 2.07x10^6 m2s-2(might have been 7 cant remember) and get 4.7x10^4Jor around that?
    Yeah something like that for the mean square speed
    But my energy was different... It was like 1.6*10^7

    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by SuperMushroom)
    For the first question on astro as it gave the distance from the sun in AU and it wanted the distance to the earth so do you take away 1AU from the largest distance given and this would give the distance to the earth


    Posted from TSR Mobile
    That's what I did. 2.57-1 AU and convert to metres. Hope that's right. I presume it wanted the distance between the centres and we didnt have to remove the radii.
    Offline

    1
    ReputationRep:
    (Original post by dominicwild)
    I initially thought this too. But I looked at the units, which were  m^2s^-^2
    So I calculated the mean. Then I just squared it all.
    Oh ok i have no clue if im right, i just remember when you derive the pressure of a gas (u1^2 + u2^2...) / Number of particles = mean squared value
    Offline

    3
    ReputationRep:
    (Original post by HenryHein)
    I think it said largest distance, so you add 1AU not take away (3.57AU in total?)
    did what i di !!!! many say taking away is right but surley if the earth is behind the sun and venus or whatever the distnce is add 1 ?
    Offline

    1
    ReputationRep:
    (Original post by Sbarron)
    Now I'm far from the best student so DON'T go by these values but I just want to see if anyone got any the same as me.....

    Nuclear and thermal:
    0.05, 5.00
    1.4*10-15 m
    5.3*10-15 m
    1.3*10^17 kgm-3
    3.3*10-6 s-1
    8.2*10^11
    47000J
    160000
    319 K

    Astro:
    2.4*10^11
    15m
    -82
    5000 K
    97*10^6
    8.8*10^21
    4.9*10^17
    I agree pretty much with all the Thermal and Nuclear ones! I did turning points section 2 though :3
 
 
 
Poll
Which web browser do you use?

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

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