A man in a boat crosses a river from point A. if the rows perpendicu lar to the bank he reaches point C(BC=120m) in 10 minutes. If the the man heads at a certain angle alpha to the straight line AB(AB is perpendicualr to the banks) against the current be reaches point B in12.5 minutes.

A man in a boat crosses a river from point A. if the rows perpendicu l

1.	A man in a boat crosses a river from point A. if the rows perpendicu lar to the bank he reaches point C(BC=120m) in 10 minutes. If the the man heads at a certain angle alpha to the straight line AB(AB is perpendicualr to the banks) against the current be reaches point B in12.5 minutes.
Answer» the width of the river is 300M the width of the river is 200m the rowing VELOCITY is 20m/min the rowing velocity is 30m/min. Solution :In the first case BC=`vt_(1)` and `w=ut_(1)`. In the second case `u sin alphat_(2)`. Solving these FOUR EQUATIONS with proper substituing , we get=200m, u=20 m/min, v=12m/min and `alpha=37^(@)`