The water used in many fountains is recycled. For instance, a singel water particle in a fountain travels through an 85 m system and then returns to the same point. What is the displacement of a water particle during one cycle?

I don't know where to start. It seems like there is not enought information, but I'm almost positive I should be able to solve it.

2 answers

The displacement is zero since it returns to the same point after one cycle. There is actually more numerical information than necessary to answer this problem. You just need to understand the meaning of displacement.
Allright. Thanks for your help! :-)