Hi, I have this excercise that I've been trying to do for a couple of days now. Can anybody help me? Here's the question:(adsbygoogle = window.adsbygoogle || []).push({});

A boat is moving against the direction of flow of a river and meets a piece of wood that is moving along with the river. The boat continues against the flow of the river for another 30 minutes and then turns around. Moving at the same speed relative to the water as before, it catches up with the piece of wood 3km from the place where they met. What was the speed of the river?

Answer: 3 km/h.

I've tried setting up all sorts of equtions of motion relative to earth (the place where they met), but haven't been successful at getting the right anwer. Should I set up the equations in terms of the point where the boat turns around?

- Kamataat

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# Homework Help: Relative motion

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