Physics  urgent!!!
posted by Sally .
A swimmer tries to go straight across a river that is 500m wide. The swimmer can swim at 1.5m/s. There is a current of .05m/s downstream. Calculate
a) the actual velocity of the swimmer
b) how long it will tale to reach the far shore
c) how far donstream the swimmer will hit the opposite shore.
So far I'm using pythagorean theorem to find the hypotenuse; I'm doing the squre root of 500^2+.5^2 and that's givving me 500.00025, but I don't really think I'm doing this correctly; I'd really appreciate some help with this. :)

No, not correct.
1) his actual velocity sqrt(1.5^2+.05^2)
2)time=500/1.5
3) distancedownstream=.05*time in b. 
oh okay, thank you.
Could you mind explainig how you got the velocity, please? 
The velocity over the ground is a right triangle sum of the across velocity plus stream velocity.

oh ok, I see that now; thank you very much! :)