A260-m-wide river flows due east at a uniform speed of 4.1m's a boat with a speed of 7 5ms relative to the water leaves the south bank pointed in a direction 37 west of north. what is the (al magnitiale and tb) direction ot the bat's velocity relative to the ground? give the direction as the anele of the velocity from due north positive if to the east and nepative if to the west. ld) how long does it take for the boat to cross the river?