Sun July 29, 2012 By:

A man can swim at a speed of 3km/h in still water.He wants to cross a 500m wide river flowing at 2km/h.He keeps himself always at an angle of 120 degrees with the river flow while swimming. (i) Find the time he takes to cross the river (ii) At what point on the opposite bank will arrive?

Expert Reply
Thu August 02, 2012
3 cos 30° would be responsible for crossing the river ie 500 m=1/2 km
time taken=1/2 ÷3?3/2
                =1/3?3  hr
on the opposite bank he will arrive=1/6?3 km
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