Question

A swimmer is capable of swimming $1.65$ $m{s}^{-1}$ in still water. If she swims directly across a $180$m wide river whose current is $0.85$ m/s, how far downstream(from a point opposite her standing point) will she reach?

• A. $92.7$ m
• B. $40$ m
• C. $48$ m
• D. $20$ m

Answer 1

The correct option is A $92.7$ m

Time taken to cross the river $t=\frac{180}{1.65}=109s$

Velocity of river $V_R=0.85m/s$

Drift $x=V_R\times t=0.85\times 109=92.7m$