Aswimmer is capable of swimming 1.20 m/s in still water. (a) if she aims her body directly across a 150-m-wide river whose current is 0.55 m/s, how far downstream (from a point opposite her starting point) will she land?

Velocity of swimmer in still water = Velocity along width of river = 1.20 m/s

So, time taken by the swimmer to cross the river = 150/1.20 = 125 seconds

So , the swimmer is going downstream for 125 seconds at a speed of 0.55 m/s

Distance traveled during that time = 0.55*125 = 68.75 m

So the swimmer will reach 68.75 m far from the point opposite to her starting point

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