Question

9. A boy swims 200 m in still water and then returns back to the point of start in total
10 minutes. Find the speed of his swim in (i) m s-1 (ii) km h-1.​

Answer 1

• Total distance coveredby the boy = (200+200) = 400m
• Time taken to cover 400m = 10 minutes = 600 seconds

(i) Speed = $\frac{400}{600}$ = $\frac{400}{600}$ = $\frac{2}{3}$ m/s

(ii) $\frac{2}{3}$ m/s = $\frac{2}{3}$ x $\frac{3600}{1000}$ km/h = $\frac{12}{5}$ km/h