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Homework Help: Distance travelled by a thrown object

  1. Jan 18, 2012 #1
    1. The problem statement, all variables and given/known data

    The diagram to this problem is of a HILL as shown:

    Point A
    -
    -
    20m
    -
    -
    ------------------------50m------------------------- Point B

    From ground level, a person at Point A throws a snowball horizontally to the right at 25 m/s. Where does the snowball land?

    a) 10m to the left of Point B
    b) At Point B
    c) 12.5m to the right of Point B
    d) 50m to the right of Point B

    2. Relevant equations

    According to the answer given (answer is B), the relevant equations are t=(2h/g)^(1/2) and d=vt

    3. The attempt at a solution

    The 4 linear motion equations I know are

    x = x + vt + (1/2)at^2
    v(initial) = v(final) + at
    v(i)^2 = v(f)^2 + 2ax
    v(avg) = (v(i) + v)/2

    I don't know the time equation listed in the answer. Is it derived from one of these equations or is it a whole different equation? I'm confused about how I was supposed to know to solve this question basically...
     
  2. jcsd
  3. Jan 18, 2012 #2

    jedishrfu

    Staff: Mentor

    if you dropped the ball how long does it take?

    then use that time to compute how far it went.
     
  4. Jan 18, 2012 #3
    I know I have to find time first, but if you read the comments I'm asking about the equation used. I have never seen it before and I'm confused about where it comes from. Is it derived from another equation?
     
  5. Jan 18, 2012 #4

    jedishrfu

    Staff: Mentor

    s= 1/2 g t^2 with s being the height of point A
     
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