# PHYSICS

TRACY SWIMS ACROSS A STREAM OF WIDTH 40.0M IN 33.0S WHEN THERE IS NO CURRENT.SHE TAKES 59.0 TO COVER THE SAME DISTANCE WHEN THERE IS CURRENT.FIND THE SPEED OF THE CURRENT RIVER.

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1. Well, the swimmers velocity in still water is 40/33 m/s=1.21m/s

Now, she is swimming some angle upstream, so the horizontal component of this velocity is 40/57 m/s

Now how far did she swim relative to the water ?

relative to water= 40/33 * 57 meters

CosTheta= 40/(40/33 * 57)= 33/57
Theta= arccos (33/57)=54.6 deg
But Tantheta= current/(40/33 cosTheta)
currentvelocity= tan54.6 *40/57=.99m/s

check my thinking.

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bobpursley
2. thanks men appreciate your help.

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