A swimmer wishes to cross a river 500m width flowing at a rate u. his speed w.r.t. still water is v. for this he makes an angle theta with the vertical as shown in the given figure then:

A swimmer wishes to cross a river 500m width flowing at a rate u. his

1.	A swimmer wishes to cross a river 500m width flowing at a rate u. his speed w.r.t. still water is v. for this he makes an angle theta with the vertical as shown in the given figure then:
Answer» to CROSS the river in minimum time `theta=0^(@)` to cross the river in minumum time, `theta=30^(@)` for u=3km/hr and v=5km/hr, the timetaken to cross the river in minimum time will be 6MIN. for u=3 km/hr and v=5km/hr, the time taken to cross the river in minimum time will be 3MIN. SOLUTION :`t=((d)/(ucos theta))` for minimum time `theta=0`.