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[DiffEq] First order Modeling Applications

  1. Sep 25, 2005 #1
    YATP - Yet Another Trainlike Problem

    Sailboats A and B each have mass 60kg and cross the starting line at the same time of a race. Each has an initial velocity of 2m/s.
    Obviously from this, m1 = m2 == 60kg and vo1 = v02 == 2 m/s.
    The wind applies a constant force of 650N to each boat and the water resistance is proportional to the velocity of the boat.
    Boat A:
    proportionality constants are b1 = 80 Nsec/meter before planing when the velocity is less than 5m/s and b2=60Nsec/m when velocity is aboce 5m/s.

    Boat b:
    proportionality constants are b1 = 100 Nsec/meter before planing when the velocity is less than 6m/s and b2=50Nsec/m when velocity is aboce 6m/s.

    The race is 500m long, which sailboat will be leading at the end of the race?

    I assume that the method of solution will be to complete the equations of motion for both then sub them for the race length but the problem that is getting me is the different constants for different times. Do I need the heavyside function or something to get this set-up.
  2. jcsd
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