How big should a water bottle rocket's parachute be?

I'm using a 2-liter bottle. Some of the sites I see tell you to make it really big, 3 feet, while say that you should make it about 1 foot in diameter, so it doesn't float too far away.

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Sep 2, 2011. 11:48 PMvsingh15 says:

Here is a link to a site: http://www.water-rockets.com/article.pl?124,0
It tells you how to make a parachute of appropriate size for a bottle rocket.
(The parachute is made out of plastic bag)

Sep 7, 2009. 1:12 PMwintv123 says:

what is the highest over 50 feet it might be useful more of just cool to watch than practical

164

Mar 10, 2009. 3:53 PM

Kiteman says:

The best answer is "it depends". If you need a soft landing. go large. If you need it to land closer, go small. In my experience, though, if you are just using a bottle, with no payload, they don't usually need any sort of parachute to survive landing.

Mar 12, 2009. 4:47 PMMePerson (author) says:

How far away does the rocket travel if you use a 3-foot parachute in 5 mph wind? I read on another website that it goes 700+ feet away, but they're assuming that it moves sideways at the same speed as the wind.

164

Mar 12, 2009. 5:14 PM

Kiteman says:

It depends how high it goes, because it will have more time to drift sideways as it falls. An empty plastic bottle, with a parachute, will easily travel at or near the speed of the wind.

Mar 10, 2009. 5:43 PMMePerson (author) says:

Alright then. I do need a parachute, as the requirements for what I am doing say so. I'll make a 0.5 meter parachute, which is about 20 inches.