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    9 A car accelerates uniformly from rest along a level road.
    The effects of air resistance on the car are negligible.
    The car travels 12m in the second second of its journey.

    How far does it travel in the fourth second?
    A 28m
    B 35m
    C 48m
    D 64m
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    (Original post by TobyReichelt)
    9 A car accelerates uniformly from rest along a level road.
    The effects of air resistance on the car are negligible.
    The car travels 12m in the second second of its journey.

    How far does it travel in the fourth second?
    A 28m
    B 35m
    C 48m
    D 64m
    Hi there, what have you tried?

    It might help if you realise that the 1st second is between t=0 and t=1 and the 2nd second is between t=1 and t=2 and so on. The way they've written it makes the question somewhat confusing.

    For this question, you have to break it up into parts.

    Consider the pieces of information you have. You know that it starts from rest so at t=0, u=0. You know that in the time interval [1,2], s=12 and you also know that acceleration is constant throughout. Do you know how you might proceed?
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    (Original post by Kvothe the arcane)
    Hi there, what have you tried?

    It might help if you realise that the 1st second is between t=0 and t=1 and the 2nd second is between t=1 and t=2 and so on. That makes the question somewhat confusing.

    For this question, you have to break it up into parts.

    Consider the pieces of information you have. You know that it starts from rest so at t=0, u=0. You know that in the time interval [1,2], s=12 and you also know that acceleration is constant throughout. Do you know how you might proceed?
    Any idea how to get 28m? as thats the answer
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    (Original post by killercreed95)
    Any idea how to get 28m? as thats the answer
    I do . Have you tried my tips?
    Please post your working.
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    Yes, I get 28 too.

    In all these questions it's best to work out what pieces of information you have and which formulas you can use.

    If you look at the first second (i.e when u=0 and t=1 ) you can deduct that for the first second v=a.

    If you look at the second second (i.e when u = a from the last step), t is again 1 and you know S. That is enough information to be able to work out a and once you know this you can complete the question
 
 
 
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