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    This question is from 2013 june ial mechanics 1 Q2, the thing that i am confused with is the anwers that the marking scheme has given.
    i tried the question by myself but the answers that i got were completely different from the marking scheme but the thing is the marking scheme does not explain how it has go to that answer
    if you do know these types please help
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    (Original post by djmans)
    This question is from 2013 june ial mechanics 1 Q2, the thing that i am confused with is the anwers that the marking scheme has given.
    i tried the question by myself but the answers that i got were completely different from the marking scheme but the thing is the marking scheme does not explain how it has go to that answer
    if you do know these types please help
    Could you tell us what the mark scheme answers are?

    And it would be useful if you post your working to show how you got different answers.
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    (Original post by notnek)
    Could you tell us what the mark scheme answers are?

    And it would be useful if you post your working to show how you got different answers.
    the marking scheme answer is 7800 for part (a), i got 1000
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    I Get 7800 too, post a pic of your working
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    it is a F = MA problem.

    F = net force downwards = gravity force - tension

    M = mass of lift + woman

    A = acceleration downwards
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    guys i got the answer, i forget to multiply the mass with G
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    (Original post by djmans)
    This question is from 2013 june ial mechanics 1 Q2, the thing that i am confused with is the anwers that the marking scheme has given.
    i tried the question by myself but the answers that i got were completely different from the marking scheme but the thing is the marking scheme does not explain how it has go to that answer
    if you do know these types please help
    First off, start off with a diagram labelling all the forces acting in the system along with the acceleration. You know that the total mass is 950 + 50 = 1000 kg and that the lift is moving upwards. The weight acts downwards with a total magnitude of 1000g N, while the tension, T, acts upwards. Since the lift moves upwards and is decelerating, which way do you think acceleration acts?

    Edit: sorry, didn't see your last post!
    Spoiler:
    Show
    \displaystyle \[R(\text{up}): \vec{F} = m\vec{a} \Leftrightarrow (T- mg) = m\vec{a}\]
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    (Original post by djmans)
    The thing is the marking scheme does not explain how it has got to that answer
    The mark scheme is just that, a scheme to assist markers and to make sure that all the examiners are marking in the same way. It is not intended to be a teaching tool.
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    (Original post by samb1234)
    I Get 7800 too, post a pic of your working
    could you help me with one more thing

    i am confused how you get another (-g) their, i found F is g but dont understand how their is another (-g). is it by 2gcos(30)?
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    (Original post by djmans)
    could you help me with one more thing

    i am confused how you get another (-g) their, i found F is g but dont understand how their is another (-g). is it by 2gcos(30)?
    Without seeing the question it's difficult to work out what the mark scheme wants
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    (Original post by samb1234)
    Without seeing the question it's difficult to work out what the mark scheme wants
    Here is the question
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    (Original post by djmans)
    Here is the question
    Fmax =muR, the reaction force is 2gcos30 which is 2g root3/2 and mu is 1/root 3 so the root 3s cancel, leaving friction force =2g/2 =g. Then the force of gravity parallel to the plane is 2g sin30, sin30 is 0.5 so that force is also g
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    (Original post by samb1234)
    Fmax =muR, the reaction force is 2gcos30 which is 2g root3/2 and mu is 1/root 3 so the root 3s cancel, leaving friction force =2g/2 =g. Then the force of gravity parallel to the plane is 2g sin30, sin30 is 0.5 so that force is also g
    thank you so much, i got confused how it became g but now i got it thanks and one more thing if they say to find the magnitude what do they mean exactly

    Eg:find the magnitude of the driving force of the truck
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    Well force is a vector, meaning that it has both a magnitude and direction e.g. you might have a force of 60N at 87degrees to the horizontal. The magnitude is simply how big the force is, so in that example the magnitude of the force is 60N. Same with speed vs velocity, velocity has a direction so speed you would simply quote the positive value so if the velocity was -5ms-1, speed is 5ms-1
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    (Original post by samb1234)
    Well force is a vector, meaning that it has both a magnitude and direction e.g. you might have a force of 60N at 87degrees to the horizontal. The magnitude is simply how big the force is, so in that example the magnitude of the force is 60N. Same with speed vs velocity, velocity has a direction so speed you would simply quote the positive value so if the velocity was -5ms-1, speed is 5ms-1
    thank you so much for the help, i have my mocks next week hopefully i do well
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    (Original post by djmans)
    thank you so much for the help, i have my mocks next week hopefully i do well
    No problem, best of luck with the mocks and if you get stuck again let me know
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    (Original post by samb1234)
    No problem, best of luck with the mocks and if you get stuck again let me know
    Hey can you help with this connected particles question
    its from 2001 paper and i am confused on part a) ive been trying for an hour but cant get the answer
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    (Original post by djmans)
    Hey can you help with this connected particles question
    its from 2001 paper and i am confused on part a) ive been trying for an hour but cant get the answer
    consider just A, what direction it is moving in and then start resolving
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    (Original post by djmans)
    Hey can you help with this connected particles question
    its from 2001 paper and i am confused on part a) ive been trying for an hour but cant get the answer
    http://www.thestudentroom.co.uk/show....php?t=3875341
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    (Original post by samb1234)
    consider just A, what direction it is moving in and then start resolving
    thx i got the answer
 
 
 
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