Compute all parts of given problem:

Problem: A 280-m-wide river has a uniform flow speed of 1.4 m/s through a jungle and toward the east. An explorer wishes to leave a small clearing on the south bank and cross the river in a powerboat that moves at a constant speed of 5.1 m/s with respect to the water. There is a clearing on the north bank 25 m upstream from a point directly opposite the clearing on the south bank.

Part I: At what angle, measured relative to the direction of flow of the river, must the boat be pointed in order to travel in a straight line and land in the clearing on the north bank?

Part II: How long will the boat take to cross the river and land in the clearing?

I don't know how to get that answer for the above problem. Please help! Thanks.