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    An object is thrown vertically downwards with speed V. During the sixth second of its motion it travels a distance h. Find V in terms of h and g.

    This is my working:

    t=6 v=V u=0 g=a s=h

    s=vt -1/2 at^2

    h=6v -1/2 xgx6^2
    h= 6v - 18g

    6v = h+18g so v = (h+18g)/6

    This is NOT the right answer. And help would be received gratefully. :-)
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    (Original post by Zarantulas)
    An object is thrown vertically downwards with speed V. During the sixth second of its motion it travels a distance h. Find V in terms of h and g.

    This is my working:

    t=6 v=V u=0 g=a s=h

    s=vt -1/2 at^2

    h=6v -1/2 xgx6^2
    h= 6v - 18g

    6v = h+18g so v = (h+18g)/6

    This is NOT the right answer. And help would be received gratefully. :-)
    If it is thrown downwards with speed V then the initial speed (u) will be V.

    It looks like you've mistaken V for the final speed instead
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    By that calculation, V =(h-18g) /6

    Unfortunately this is still not the textbook answer but thanks anyway!
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    (Original post by Zarantulas)
    By that calculation, V =(h-18g) /6

    Unfortunately this is still not the textbook answer but thanks anyway!
    The object travels a distance h during the 6th second, it hasnt travelled a distance h after the sixth second of motion.
    Does that help?
 
 
 
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