A swimmer crosses the river so as to reach the opposite point, along the line making an angle of 45o with the direction of flow. Velocity of the river water is 5 m/s. Swimmer takes 12 seconds to cross the river of width 60 m. The velocity of the swimmer (in m/s) with respect to flowing water will be:
We have, breadth of the river as B=60 m and time take to cross the river as t=12 s.
vy=Btvy=6012=5 m/s
For 45o angle
vx=vy∴vx=5 m/s−→vM=5^i+5^j−→vR=5^i∴−−→vMR=−→vM−−→vR=5^j
−−→vMR=5 m/s