47.A man can row a boat with 4kmph in still water.If he is crossing a river where the current is 8kmph .The time take to cross the river in shortest path is (k)/(sqrt(3))hr .Where k ' is (width of the river is 8km )

A man can row a boat with 8 kmph in still water.If he is crossing a river of width 8km where the current is 4kmph , then the time taken to cross the river in shortest time is (k/sqrt(3)) hr.The value of 'k' is?

A river flows at the rate of 3km/hr and a person can row a boat at a speed of 5km/hr in still water.If the difference between the times taken to cross the river by the shortest path and the quickest path be 4 minutes,the width of the river is (in km)

A man can row a boat with 4km/h in still water, if he is crossing a river where the current is 2 km/h. (a) In what direction will his boat be holded, if he wants to reach a point on the other bank, directly opposite to starting point? (b) If width of the river 4km, how long will the man take to cross the river, with the condition in part (a)? (c) In what direction shou ld he heat the boat if he wants to cross the river in shorest time and what is this minimum time? (d) How long will it take him to row 2 km up the stream and then back to his starting point?

A man can row a boat with 4km/h in still water, if he is crossing a river where the current is 2 km/h. (a) In what direction will his boat be holded, if he wants to reach a point on the other bank, directly opposite to starting point? (b) If width of the river 4km, how long will the man take to cross the river, with the condition in part (a)? (c) In what direction shou ld he heat the boat if he wants to cross the river in shorest time and what is this minimum time? (d) How long will it take him to row 2 km up the stream and then back to his starting point?