Posted by Zoe on .
The water in a river flows uniformly at a constant speed of 2.53 m/s between parallel banks 69.8 m apart. You are to deliver a package directly across the river, but you can swim only at 1.74 m/s.
(a) If you choose to minimize the time you spend in the water, in what direction should you head? ____° from the direction of the stream
(b) How far downstream will you be carried? ______m
(c) If you choose to minimize the distance downstream that the river carries you, in what direction should you head? ____° from the direction of the stream
(d) How far downstream will you be carried? _____m

I know we're dealing with motion in 2D, but I don't even know which equations to use or how to start. Any help or jumpstarts will be greatly appreciated.

Physics 
Maria,
A ball is tossed from an upperstory window of a building. The ball is given an initial velocity of 7.70 m/s at an angle of 23.0° below the horizontal. It strikes the ground 6.00 s later.
(a) How far horizontally from the base of the building does the ball strike the ground?
(b) Find the height from which the ball was thrown.
(c) How long does it take the ball to reach a point 10.0 m below the level of launching?