Physics questions?

[Dreams]

A swimmer can swim in still water at a velocity of 2 m/s. A current of 1 m/s flows in a river 10 m across.
a) If the swimmer heads out directly across the river, where will the swimmer come to shore on the opposite bank? What is the swimmer's velocity?
b) What heading should the swimmer take to land on the shore directly opposite? Would this affect the swimmer's velocity?
c) Assuming the swimmer cannot swim any faster than 2 m/s, is there a threshold limit to the current that would prevent the swimmer from swimming directly across the river? Would the width of the river matter?

Last question...
A 5.0 kg mass rests on a level, frictionless table, attached to a 3.0 kg mass suspended in the air by a light string that passes over a frictionless pulley. Calculate the tension in the string when the masses are released. If the coefficient of kinetic friction between the table and the mass is 0.3, how does this change?

Help is Appreciated!

[holdm]

a) 5m downstream. it takes the swimmer 5s to cross the river. during that time, the river moves 5m downstream.

b) aim 5m upstream (the heading is arctan(1/2). we have the same 5, 10, 5sqrt(5) triangle, but now the swimmer takes the hypoteneuse. this does not affect the swimmer's velocity, but it does effect the time spent to cross the river.

c) as long as the current is finite, he can get to his spot. arctan(current/2) is the angle. he might have to travel at very close to parallel to the shore, but he'll get across eventually.