Ariver has a steady speed of vs. a student swims upstream a distance d and back to the starting point. (a) if the student can swim at a speed of v in still water, how much time tup does it take the student to swim upstream a distance d? express the answer in terms of d, v, and vs. tup = incorrect: your answer is incorrect. (b) using the same variables, how much time tdown does it takes to swim back downstream to the starting point? tdown = incorrect: your answer is incorrect. your answer cannot be understood or graded. more information