A river has a constant current of 2 kilometers per hour At w

A river has a constant current of 2 kilometers per hour. At what angle to a boat dock should a motorboat, capable of maintaining a constant speed of 25 kilometers per hour, be headed in order to reach a point directly opposite the dock? If the river is 1/4 kilometer wide, how long will it take to cross? At what angle should the boat be heading relative to the boat dock which is orthogonal to the curve (Do not round until the final answer. Then round to one decimal place as needed.) How long will it take for the boat to cross the river? hours (Do not round until the final answer. Then round to two decimal places as needed.)

Solution

time = d/vcos4.6 = 0.25/25cos4.6 = 1/(100cos4.6) = 0.010032154 hr

= 0.60193 min = 36.116 sec