(Hope this is in the right forum) For my A Level coursework I have to do a practical investigation. I'm thinking of doing one looking at the efficiency of a siphon. One relationship I am going to be looking at is the rate of flow vs height (difference between the two water levels). Now I'm having a bit of difficulty thinking what else I can look at to give it some decent scope. My teacher hasn't seen this done before so we're a bit uncertain whether it's worth taking forward. Any suggestions would be appreciated! Thanks.