On their way to play soccer in the World Cup, Brandi and Mia get stranded in the Chicago airport because of bad weather. Late at night, with nobody else around, they decide to have a race to prove who is faster. First they run down to a particular point, then they turn around and return to their starting point. That race turns out to be a tie.
They then decide to race with one of them (Mia) running on a moving sidewalk. Once again they start at the same time, run east at top speed a distance L through the airport terminal, and then turn around and run west back to the starting point. You can assume that Brandi runs at a constant speed of v. Mia runs on a moving sidewalk that travels at a speed of v/2; she runs at a constant speed of v relative to the moving sidewalk.
Who wins this race?