Turn on thread page Beta
    Offline

    2
    ReputationRep:
    (Original post by sequence123)
    What sort of raw mark do you usually need for an A?
    60 is usual
    Offline

    2
    ReputationRep:
    What I was saying is that for a lamina, since it has area, 'm' must equal the mass per unit area, where as for a wire it has no area, only length, so 'm' is instead mass per unit length.

    This does not affect the position of the centre of mass directly because for a uniform lamina the centre of mass will always be at the same point regardless of the laminas weight, same with a wire (midpoint of each length).

    sectors and arcs are the same. if you have an arched wire, you have the position of centre of mass for a uniform wire arc, (rsinθ/θ) and the centre of mass for a uniform sector lamina (2rsinθ/3θ). Those positions will not change, regardless of the masses.
    Offline

    0
    ReputationRep:
    hello all - i think it was an easy paper.
    i am confident i got all right except for one question
    for this one question, i just would like some people's opinion:

    the coefficient of restitution question:
    the mass of A=3m, B=2m, C=5m.
    however for part b) where you have to show there's no collisions, i accidently used B=3m (yes very stupid mistake). and that was worth 7marks unfortunately. just wondering - how many marks would i get then out of 7? i still showed no collisions . just wrote the wrong value for the mass of B. very unfortunately mistake that i seem prone to. probably thrown my 100 out of the window and messed my chances of 600 this year
    Offline

    0
    ReputationRep:
    usually around 60/75 for an A
    Offline

    0
    ReputationRep:
    (Original post by ArVi)
    for the first question, part (b) - the new max speed the car can travel up the slope - did anyone get 14∟7∟12 (thats supposed to be 14 and 7/12)?
    yup..i got 14.6m/s
    Offline

    2
    ReputationRep:
    Didn't preview that one did I... the smiley face intrusions were actually meant to be

    rsinTHETA/THETA and 2rsinTHETA/3THETA respectively...
    Offline

    6
    ReputationRep:
    Most probably got a B or a C
    Offline

    2
    ReputationRep:
    (Original post by Zuber)
    very unfortunately mistake that i seem prone to. probably thrown my 100 out of the window and messed my chances of 600 this year

    You must be devestated
    Offline

    0
    ReputationRep:
    btw did anyone find question 6c rather odd for a 2marker? i.e. the rod was replace by a longer lighter rod that extended to the mid-point of the shape. then show that the force exerted at the point A was horizontal...
    i managed to do it, but with about 1/2 a page of working out!! (calculated new T=60g, and the angle was 60 between T and vertical)
    Offline

    1
    ReputationRep:
    im feelin an E comin ma way
    Offline

    0
    ReputationRep:
    (Original post by chats)
    You must be devestated
    hey wat about me
    i feel ignored :blushing:
    Offline

    0
    ReputationRep:
    (Original post by Zuber)
    btw did anyone find question 6c rather odd for a 2marker? i.e. the rod was replace by a longer lighter rod that extended to the mid-point of the shape. then show that the force exerted at the point A was horizontal...
    i managed to do it, but with about 1/2 a page of working out!! (calculated new T=60g, and the angle was 60 between T and vertical)
    nope was easy.... jus took moments about Midpoint of AB. and found there were no moments either way so vertical component had to be 0.
    Offline

    2
    ReputationRep:
    (Original post by hajira)
    hey wat about me
    i feel ignored :blushing:
    you're just great
    Offline

    0
    ReputationRep:
    (Original post by chats)
    You must be devestated
    lol. not really. i know that personally i deserved those marks (just accidently used mass 3 instead of 2). i wish the markers could just ignore such silly mistakes!! making mistakes like that really hasnt got anything to do with maths! and i checked, when i did use the mass of B as 3m, all my algebra was perfect
    Offline

    0
    ReputationRep:
    (Original post by Zuber)
    lol. not really. i know that personally i deserved those marks (just accidently used mass 3 instead of 2). i wish the markers could just ignore such silly mistakes!! making mistakes like that really hasnt got anything to do with maths! and i checked, when i did use the mass of B as 3m, all my algebra was perfect
    LoL id get 100 on every paper :P everyone would
    Offline

    2
    ReputationRep:
    (Original post by Zuber)
    lol. not really. i know that personally i deserved those marks (just accidently used mass 3 instead of 2). i wish the markers could just ignore such silly mistakes!! making mistakes like that really hasnt got anything to do with maths! and i checked, when i did use the mass of B as 3m, all my algebra was perfect
    Well if its as hard as everyones saying then the raw mark for 100UMS could be 69/75

    You might still have your 100% record
    Offline

    0
    ReputationRep:
    (Original post by chats)
    you're just great
    haha thanx

    i was refering to my mistake that got burried in the posts lol..
    how many marks was the CoM question?
    made an arithmetic mistake there
    Offline

    0
    ReputationRep:
    (Original post by Syncman)
    nope was easy.... jus took moments about Midpoint of AB. and found there were no moments either way so vertical component had to be 0.
    ahhhhh i see (duh). my way still worked though . and i have confirmed it at home. its a different method (much longer). hopefully i should get the marks!
    Offline

    0
    ReputationRep:
    (Original post by Syncman)
    LoL id get 100 on every paper :P everyone would
    not really. i mean most marks on maths papers arent lost by non-mathematical mistakes (like using the wrong mass) but by a slip up in algebra, or changing a plus to minus... or so i think
    Offline

    0
    ReputationRep:
    btw, no-one has told me what they think i could get out of 7 for 5b)...anyone have any idea?
 
 
 
Turn on thread page Beta
Updated: June 26, 2005
The home of Results and Clearing

2,380

people online now

1,567,000

students helped last year

University open days

  1. Keele University
    General Open Day Undergraduate
    Sun, 19 Aug '18
  2. University of Melbourne
    Open Day Undergraduate
    Sun, 19 Aug '18
  3. Sheffield Hallam University
    City Campus Undergraduate
    Tue, 21 Aug '18
Poll
A-level students - how do you feel about your results?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

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.