Answer:
Rowboat arrives 0.558 miles to the upstream when it reaches the opposite shore.
Explanation:
Velocity of rowboat = 3.30 mi/h
Angle with north of west = 62.5⁰
Width of river = 0.505 mile.
Velocity of river = 1.25 mi/hr eastward.
Let us take east as positive X -axis and North as positive Y-axis.
So angle of boat with horizontal axis = (90+62.5) = 152.5⁰
Horizontal speed of boat = 3.30*cos 152.5 = -2.93 mi/h
Vertical speed of boat = 3.30*sin 152.5 = 1.52 mi/h
Horizontal speed of river = 1.25 mi/h
Time taken to cross river = Width of river/Vertical speed = 0.505/1.52 = 0.33 hour.
Velocity along upstream of river = -2.93+1.25 = -1.68 mi/hr
So distance moved along upstream = -1.68*0.33 = -0.558 miles ( negative sign means along west direction)
It reaches 0.558 miles to the upstream when it reaches the opposite shore.
