Solution:
V_{AW} = V_{AS} + V_{SW}
where V_{AS }= 5.0 m/s with the course 30^{0} North of East
V_{WS }= 1.5 m/s in the direction of South
thus,
V_{SW }= 1.5 m/s in the direction of North
We can now draw the vector diagram the represents the vector equation.
We can now solve for V_{AW}.
b) The distance upstream is easily solved by determining the time of crossing using V_{ASx} and
then calculating vertical displacement using V_{ASy}.
c) The vector equation for the velocity of the boat with respect to the
shore is given by,
V_{BS} = V_{BW} + V_{WS}
where V_{BW }= 2.5 m/s with a heading of 55^{0} South of East
V_{WS }= 1.5 m/s in the direction of South
The vector diagram should be drawn to aid in seeing the following calculations.
d) The time to cross the river is then simply calculated using the width of the river and the
xcomponent of V_{BS}.
Top of Page 
