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    when using deceleration in a Suvat formula do we automatically use a minus sign in it when plugging it into a formula?

    eg: s: 200 u:20 v:? a: 1.5m/s ( decelerating, do I put minus infront before using formula?)

    cheers
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    (Original post by upthegunners)
    when using deceleration in a Suvat formula do we automatically use a minus sign in it when plugging it into a formula?

    eg: s: 200 u:20 v:? a: 1.5m/s ( decelerating, do I put minus infront before using formula?)

    cheers
    depends on the +ve direction chosen
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    (Original post by upthegunners)
    when using deceleration in a Suvat formula do we automatically use a minus sign in it when plugging it into a formula?

    eg: s: 200 u:20 v:? a: 1.5m/s ( decelerating, do I put minus infront before using formula?)

    cheers
    v^2 = u^2 + 2as

    v^2 \geq 0
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    (Original post by TenOfThem)
    depends on the +ve direction chosen
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    its that question, it's only 2 marks but using the values I have stated (without taking the minus of the acceleration) I got 30.1m/s which is impossible as he is decelerating from 20m/s..
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    (Original post by upthegunners)
    when using deceleration in a Suvat formula do we automatically use a minus sign in it when plugging it into a formula?

    eg: s: 200 u:20 v:? a: 1.5m/s ( decelerating, do I put minus infront before using formula?)

    cheers
    when choosing right as the positive direction, I would use the formula normally, and yeah you would use -1.5 for a
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    (Original post by upthegunners)
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    its that question, it's only 2 marks but using the values I have stated (without taking the minus of the acceleration) I got 30.1m/s which is impossible as he is decelerating from 20m/s..
    In that case -ve as you will be looking at +ve t
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    (Original post by TenOfThem)
    In that case -ve as you will be looking at +ve t
    what do you mean?
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    (Original post by upthegunners)
    what do you mean?
    Sorry, complete lack of clarity in my previous response

    Graph questions (and horizontal motion generally) just has +ve "to the right" or in the direction of +ve time

    When I mentioned +ve direction I was really referring to vertical questions
 
 
 
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