Question

An excellent swimmer is confident he can judge his speed in the water exactly. He bets he can swim two lengths of a 50-meter Olympic size pool at an average speed of precisely 2 meters per second. On his first lane he is a little bit slow and ends up going at 1.5 meters per second. Which average speed does he have to reach on his second lane to win the bet?

Answer 1

First lane:

V = 1.5 m/s
D = 50 m
t = D/V = (50m/1.5m/s) =

Total time to win the bet

V = 2m/s
D=100m
t = 100m / 2m/s = 50 s

Second lane

t left = 50 s - 50/1.5 s
D = 50 m

V = D/t = 50m/[50 -50/1.5] = 3m/s

Answer: he needs to average 3 m/s on the second lane to wing the bet.