Question

A river is flowing from west to east at a speed of 8m/min, a man on the south bank of the river , capable of swimming at 20m/min in still water, wants to swim across the river in the shortest time. He should swim in a direction of a) due north b) 30 degree east of north c) 30 degree west of north d) 60 degree east of north

Answer 1

A river is flowing from west to east at a speed of 8m/min, a man on the south bank of the river , capable of swimming at 20m/min in still water, wants to swim across the river in the shortest time. He should swim in a direction of a) due north b) 30 degree east of north c) 30 degree west of north d) 60 degree east of north

Answer 2

X = Vw = 8 m/min.
Y = Vs = 20m/min.

Tan A = Y/X = 20/8 = 2.500.
A = 68.2o N. of E. = 21.8o E. of N.

Direction = 21.8o W. of N. to offset
affect of the wind.

C is the closest answer.

Answer 3

Answer will be (A) - due north