A person can swim in still water at the rate of 1km/hr. He tries to cross river by swimming perpendicular to the river flowing at the rate of 2km/hr. if the width of the river is 10m find the location of the point where he lands on the other side of the river , also find time taken by him to cross the river. (Answer Fast)

Width of the river = 10 m = 0.01 km
Velocity of the river = 2 km/h
Velocity of the man = 1 km/h 
Location of the point other side the river  , x = 0.01 × 2 / 1 = 0.02 km = 20 m

Time taken to cross the river , 
 t=s2+x2v22+v12=0.012+0.02222+1=5×10-45=10-2 = 0.01 hr
 

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First convert 10m to km =0.01km

then divide 0.01km by the persons speed= 0.01hr

then convert this in seconds by multiplying by 3600

time taken 36 seconds

to find where he lands just muliply the rivers speed by time taken to reah other side.

he lands approx. 20 m away. (exact 19.9999998m)

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