Re: diff eq word problem HELP

la.foma@xxxxxxxxx writes:

problem is the following

A man swims across a river 100ft wide, always heading for a tree
directly across from his starting point. He can swim at the rate of 3
ft/sec
Find the equation of his path if the current is carrying him
downstream at the rate 2ft/sec, 3 ft/sec, 5 ft/sec

all comments on how to solve this are welcome and are appreciated!

Hint:
Let's say his target is at x=0,y=0, the river is flowing in the positive x
direction, and he starts out at x=0, y=-100.
When he is at point (x,y), what are the x and y components of his velocity?
Note that dx/dy = (dx/dt)/(dy/dt).
Come back when you have the differential equation, if you need more help then.
--
Robert Israel israel@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Department of Mathematics http://www.math.ubc.ca/~israel
University of British Columbia Vancouver, BC, Canada
.

Relevant Pages

  • Re: diff eq word problem HELP
    ... A man swims across a river 100ft wide, always heading for a tree ... downstream at the rate 2ft/sec, 3 ft/sec, 5 ft/sec ... Should be in standard differential equations textbooks. ...
    (sci.math)
  • diff eq word problem HELP
    ... A man swims across a river 100ft wide, always heading for a tree ... downstream at the rate 2ft/sec, 3 ft/sec, 5 ft/sec ...
    (sci.math)