1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook