A Water-Powered Jetpack(popsci.com)
popsci.com
A Water-Powered Jetpack
http://www.popsci.com/diy/article/2009-07/water-powered-jetpack
11 comments
I'll be the first to say that is awesome and I hope its not vaporware.
This does look like a ton of fun, though the "hose" attachment didn't seem to go too far. It's also not cheap. But kudos to the developer of the thing! It's an incredibly original invention and application. Plus, since it runs in the water and is attached to something you can't go too high and there's a smaller risk of injury.
Also, I chuckled at the pun of calling this "vaporware" :)
Also, I chuckled at the pun of calling this "vaporware" :)
"incredibly original"
Well, we can't be sure about that: ;)
http://en.wikipedia.org/wiki/Super_Mario_Sunshine
Well, we can't be sure about that: ;)
http://en.wikipedia.org/wiki/Super_Mario_Sunshine
I'm sure with a more powerful engine (which is planned), longer hoses will become possible. However, it says that the drag caused by the boat added significant stability during forward flight, so a short hose attachment actually increases the quality of the flight.
If it's not too expensive I can definitely see this becoming very popular. Looks way more fun then a jetsky.
They say it's planned to cost $130,000. You can get quite a few jet-skis for that.
I'm not a physicist, but this paragraph struck me as incorrect (or at least misleading):
Li, however, figured that if he attached a hose to his pack, and put the engine and water pump in a separate vessel that dragged behind him, he could seriously reduce his weight, and therefore the amount of thrust needed to stay aloft.
If the engine and pump were part of the jet pack, even if the engine and water pump were weightless, wouldn't it be impossible to get enough thrust to provide lift? The propellant is being thrown back in the direction it came, so doesn't the momentum cancel out?
Li, however, figured that if he attached a hose to his pack, and put the engine and water pump in a separate vessel that dragged behind him, he could seriously reduce his weight, and therefore the amount of thrust needed to stay aloft.
If the engine and pump were part of the jet pack, even if the engine and water pump were weightless, wouldn't it be impossible to get enough thrust to provide lift? The propellant is being thrown back in the direction it came, so doesn't the momentum cancel out?
There's a great deal of extra momentum being added through the engine and water pump that you're not accounting for.
That thing would rip your feet off if you got in its way.