Trevor can row a boat at 3.00 mi/hr in still water. He needs to cross a river that is 1.20 miles wide with a current flowing at 1.60 mi/h. Not having his calculator ready, he guesses to go straight across, he should head 60.0 degrees upstream with respect to straight across. a) what is his speed with respect to the starting point on the shore? b) how long does it take to cross the river? c) what should the angle have been to have gone directly across the river?