1. The problem statement, all variables and given/known data (I'm translating the problem from Slovak, so it might sound a bit choppy at times-my apologies) There's a road. On the road, there's a moving vehicle carrying a tree log, and a tourist is walking alongside the vehicle. The tourist's velocity is 2 m/s, and he wants to know how long the log is. When he walks from the front end to the back end of the log (keep in mind the log is moving in the opposite direction) he counts 16 steps. When walking from the back end to the front end of the log, he counts 112 steps (the vehicle is now moving in the opposite direction than the tourist). The length of his step is 0.75 m. a) What is the velocity of the vehicle? b) What is the length of the log? 2. Relevant equations s=t.v s....trajectory t....time v....velocity 3. The attempt at a solution I'm rather stumped. I converted the tourists steps: It took him 12m and 6s to walk from the front to the back end of the vehicle. It took him 84m and 42s to walk from the back to the front end of the vehicle. And that's about as far as I got. I could calculate the vehicle velocity if I had the log length, just like I could calculate the log length if I had the velocity. But having neither? I also deduced he must be moving quicker than the vehicle, because he managed to reach the front end from the back one. Thanks for any help.