Two identical carts are released from rest at the same time. Cart A travels down a straight incline, while cart B travels down a path that dips below that of cart A and then returns to the same level as that of cart A.

Which cart wins the race?

1. Cart A (4/33) (12%)
2. Cart B (2/33) (6%)
3. It's a tie (27/33) (82%)

The one thing that should be equal for the two carts is the speed at the bottom. They both experience the same change in potential energy, so their final kinetic energies should be equal.

Cart A travels the shortest path, but it picks up speed gradually all the way down the incline. In contrast, cart B drops quickly to a lower level and picks up more speed. It then travels at a higher speed over the lower part of its track. B wins the race because its higher average speed more than makes up for the extra distance traveled.