I don't really know if I can use this. But this pooch Maxine lives a few doors down from my parents and does this routine for every passerby. It reminds me of that problem where the fly is flying between the two trains. (Would need a better quality video for class, natch. Unfortunately I don't have a rolling-tripod thing, and the walking is kind of critical. Maybe someone stationary could tape both the walker and the dog.)
The obvious question is "How far does Maxine run?" but a more critical thinking question would be "What minimum information do you need to determine how far Maxine runs?" What do you all think?