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Homework Help: Projectile motion

  1. Nov 11, 2006 #1
    Frendz , here is a problem of motion in 2 dimensions. I simply stuck in basics .

    A man wants to cross a river 100mt long He has a velocity of 10m/s in still water and river has a velocity of 20m/s. What angle should he make with flow of river so that displacement from where he started initially should be minimum?

    I guess some concept of maximum and minimum will be used here but I don’t know how to apply
  2. jcsd
  3. Nov 11, 2006 #2
    Think of this in terms of vectors. I think the question is asking for the man's down-river vecocity to be 0 and his velocity across the river to be a maximum. Let us know if you need further assistance.
  4. Nov 11, 2006 #3
    No need to shout. This is not a projectile question but instead a vector question. Resolve the rivers vectors horizontally and vertically first.
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