Science

A girl standing on a bridge throws a stone vertically downward with an intial velocity of 15.0 m/s into the river below. If the stone hit's the water 2.00 seconds later what is the height of the bridge above the water?

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  1. h=vi*t+1/2 a t^2
    h=-15*2-4.9 *4
    h=-30-19.6=-49.6m to the water, so the height of the bridge is 49.6 above the water.

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    bobpursley
  2. Everything up is positive
    Everything Down is negaitive

    velocity initial = -15.0m/s
    distance final = 0m
    distance initial = ?
    time = 2s

    df=v * t+di
    0 = -15 * (2)+di
    di = 30 m
    therefor the bridge is 30m ablive the water.

    Not sure if this is entirely correct.

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  3. physics Kid: Nope, it is not correct.

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    bobpursley

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