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.