Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    Offline

    2
    ReputationRep:
    (Original post by Ewanclementson)
    Having checked the answer you agreed with for Q5, I do disagree. The centre of mass was a distance of root(10)/2 from the pivot.
    m(2a)+m(a)=2mx leads to x=1.5a then the centre of mass was 1.5a below L and by symmetry, 0.5a from l which gives root(10)/2.
    what do you mean? this was random's answer and that was what I put.
    Offline

    6
    ReputationRep:
    I was saying that I think random's answer which had a root2 in was incorrect (and you said you put what he did). I believe 8752 is correct
    Offline

    1
    ReputationRep:
    (Original post by Ewanclementson)
    I was saying that I think random's answer which had a root2 in was incorrect (and you said you put what he did). I believe 8752 is correct
    Offline

    1
    ReputationRep:
    (Original post by 8752)
    Yes you're right it does lie on the line joining the two masses. The distance should be root10/2 a however. Im curious as to how people got root 2 tho?
    Incorrect use of the cosine rule: if you do it with the measurements on my diagram you would get csquared as
    5/2, rooting that gives root10/2, but for some reason instead of taking moments I used cos rule just a tiny bit wrong like this Name:  image.jpg
Views: 194
Size:  499.7 KB
    by a factor of 2 in the term with cos145 gcse tier error tbh
    Offline

    1
    ReputationRep:
    Just got hold of the paper and had a go myself.
    Question 4 is ambiguous in that it's open to interpretation (with or without caps?). I've included both possibilities.
    Attached Images
  1. File Type: pdf 6681_01_que_20160621.pdf (289.0 KB, 81 views)
  2. File Type: pdf M5 2016.pdf (136.3 KB, 106 views)
    Offline

    14
    ReputationRep:
    (Original post by kloitrell)
    Just got hold of the paper and had a go myself.
    Question 4 is ambiguous in that it's open to interpretation (with or without caps?). I've included both possibilities.
    If you look in the formula book that Edexcel give you, the M of I of a cylindrical shell is given as being the same as for a hoop. That tells you that the shell does not have caps.
    Offline

    18
    ReputationRep:
    (Original post by tiny hobbit)
    If you look in the formula book that Edexcel give you, the M of I of a cylindrical shell is given as being the same as for a hoop. That tells you that the shell does not have caps.
    I think it should always be stated though. I did both ways aswell but it really should be stated.


    Posted from TSR Mobile
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: June 24, 2016
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?

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

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