Sunday, March 04, 2007

It's Rocket Science


Early Steam Rocket. Production was discontinued after it was discovered there is no coal on the moon.

I have a small but esteemed readership of an eclectic nature including, but not limited to, Weasels in the forests of Maine, Ghetto Fighters in LA, Irish Mad Scientists in Toronto, Las Vegas Megalomaniacs Looking For Love. Ok that’s step one, COMPLIMENT, then it says here…oh yeah…step two GET TO THE POINT…perhaps one of them could help me with the following.

It is a physics problem…where are you going? Come back! I’ll post the music quiz later today…I’ll let you win!

Obviously rockets are traditionally long and pointy-like, but they use rapidly expanding gasses from burning fuel. A water rocket works from air pressure (like a compressed spring) in the top of the rocket, forcing out water (which does not compress) in the bottom of the rocket. The force of the water leaving pushes the rocket in the opposite direction.

I need water under pressure to escape a vessel with maximum velocity. A narrow opening will increase velocity of course, and a long narrow opening will allow the water to reach maximum speed before escaping. All good there.

Q: Does it make a difference what shape the reservoir (rocket body) is? A fat, dumpy tank so we have a big surface area pushing on the water? Long and narrow so we have possibly more sustained pressure? Tapered for ease of flow? Or does it not make a difference?

Don’t worry about aerodynamics for now, just pressure, flow and velocity. I’ll post video if we can get it going. The benchmark is: It has to fly further than I could throw it. Thanks.

SJ

Music quiz later today.

7 comments:

Amanda said...

hmm, yeah. *cough* physics.
If it's green or wriggly it's biology. If it is smelly it's chemistry. And if it doesn't work it's physics.
Microbiology and some chemistry questions I may be able to help...
otherwise all I can add is - 'It could be the discombobulator'

Wisdom Weasel said...

Oooh bugger, this is hard. I'll ask my dad, he's an aero-engineer.

Ghetto Photo Girl said...

Turns out sleeping with an engineer doesn't actually impart any of their technical knowledge on you. It just makes you sticky.

SkookumJoe said...

Well thanks anyway for making the effort Exxy.

Ghetto Photo Girl said...

Anything for you, Skooky.

Wisdom Weasel said...

Thought you might like to know that father is circulating this through the air engineering branch of the British ministry of defence to see if any of them can come up with an answer.

SkookumJoe said...

Thanks Weasle. That is so very awesome!