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Accelerative problem... Answered

Ok I'm in the planning stage of a secret project that is going ot be very risky if it isn't right, I need to accelerate ~100kg from ~20km/h to ~100km/h (I gave it all metric to help) over a reasonably short period of time, any improvement on 100km/h is welcome because I've done this without rockets in the past. Can anyone give me any idea where to get rockets that would be of suitable power, the largest estes rocket peaks at 25N of thrust and falls to 10N of thrust for only 2.5s after this, 10 of them would cause an acceleration of 1.41666. m/s2 which isn't much use to me. Unless I did my maths wrong, it's been a good while since i've done anything like this... Basically I'm looking for thrust and alot of it, preferably from something inexpensive but on this one I wouldn't mind paying a bit... Also I did look at the homemade candy rockets but I wasn't sure I'd be able to achieve the amount of thrust safely...


Huge trebuchet?

Giant crossbow (with a truck leafspring for the bow, winched back)?

A big engine running a single wheel, lower the wheel on top of The Thing, it shoots out (like a giant paper plane launcher )

I like the crossbow idea that needs to live in the experiments bin, think more like ten of them though welded in to a bow and the steelcable for string, attatched to a tesco shopping trolley, now it's a chav cannon (we'll lure them in with promises of burberry and E's)

If the rocket bike is too safe when finished then it'll bore me in to jet pack territory.

For our colonial readers, chavs are a UK social group who would like to be rick black rapper gangsters, but are nearer to being urban rednecks than anything else.

Google images

strangely we're the only country in the world with chavs, well maybe southern ireland, nowhere else has a problem like it, everyone has gangs so do we but not chavs...

No, america has them as well. They just don't have a name (other than 'that idiot') as far as I know. Tend to have cheep cars with expensive speakers : P

wiggers thats what they are called around here(north carolina, USA) i think you all can figure out why.... i dont mean to steal your thread but i need help with something similar(but on a WAY smaller and non dangerous scale lol) i need ~1cm of downward pull to pull something up ~6 cm. the downward pull is a constant thanks in advance (i hate to ask questions on another thread but i posted a topic and nobody responded and this is sorta an emergency...)

Nah these are a race in their own right, though they have a culture of ricer like cars, except more homemade solutions like cutting a hole in the exhaust and a 20 quid induction kit added incorrectly, usually in front of the airbox (so it damages power output) And they don't have expensive speakers, they steal your hifi and stuff it in the boot. that and chavs come in their thousands, all live in estates and have encompassed many other stupid cultures, mostly though simply the dregs of the gene pool... ok that was a joke but there's a similar effect to inbreeding seen after only three generations closed in one estate...

...the dregs of the gene pool...

I prefer to think of the shallow end of the gene pool.

In fact they're skimming it, it's like the sea and ponds, all the scum floats to the top...

When the term colonial is used.. Does that refers to people from former british colony?

Yes, particularly those impish young "Americans".

I like that, you should definitely build a chav cannon!Can't even walk across the park anymore without some snotty little 16 year old in a tracksuit asking "Yo mate, got a spare fag innit? I hate them, I HATE THEM!!! murderdeathkill.

It's alright I get ayyyye mate got spare feg, i'll do yer ma's knees in if ya don't leek.... I know the pain so chav cannon then?

no it should have two and a mini one for their assortment of unsually agressive and misshapen animals

the flywheel principle. besides gravity, that was the first way of accelerating roller coasters. how about a rail gun? that could certainly provide some good acceleration, assuming your object is metallic and magnetic.

What if it's a human missile? Being on a rail-gun would make your fillings ache ...

humans lake enough magnetic surface area to be used in rail guns.

That's the point - your fillings would go, but not you ...

actually, i doubt your fillings would be large enough. plus, modern fillings are plastic.

It. Was. Meant. Humorously.

(Most UK fillings are still mercury amalgam)

*Points to braces which have been proven magnetic...*

Resists urge to ask if they pick up FM stations

I do get a little electricty, but I need a control to see if its the braces or just the properties of the human mouth...

I haven't tried though, FM is so x years ago ;P

Hah!, I remember the controversy when UK national radio stations stopped broadcasting in AM...

Heh, here a national AM radio satation is just... unheard of, nevermind FM!

NPR on FM excluded of course ( National Public Radio )

oh my god im a 15 year old senior citizen. i listen to that radio station lol... did you hear the segment about how someone went to a mall and tested the sexual attraction of deeper voices vs. highpitched voices? apparently people with deeper voices have lower immune systems so thats a sign that they are stronger the the highpitched people(they are still alive and kickin even with a lower immune system)

Hmmm, well it won't be long before some of you will be able to (kind of) hear my voice (it sounds kind of cartoonish, really), once I get all my videos uploaded and my first Instructable published.

I listen almost exclusively to NPR, and I am not a senior citizen....yet. ;-)

But I have to also put up with my wife whining "can't we listen to SOMETHING ELSE *LOL*

hahahahahaha it seems like you are the only one besides me who appreciates odd-ball programs like these lol. i discovered NPR because thats all my grandparents listened to when we lived with them lol i like the little clips of music they occasionally play. they are interesting. but i do not care for the program where they talk about what wines go with what foods.

Desert Island Disc, Radio (something or other, out of NY, I posted a few links somewhere about them....really cools stuff, but long programs)

actually, on really cheap fm radios, the reception improves on some stations when i back away from the radio. especially when im not between the radio and a window. damn braces

It seems to be associated with personal chemistry too. I remember having a Radio Shack transistor radio in my "baby carriage VW" with the top down, and a friend along. When he touched the aerial, the signal was blocked and when I touched it, the signal became stronger. It was hilarious, but we never did find out exactly why that was so.

im sure they actually could pick up am, assuming you had the variable capacitor and the carrier wave antenna externally.

actually a fair bit of it is, I suppose the flywheel principle would work, only problem is that makes me the weak link, I can hack 6G's but never have I been over that so results could be dangerous, on the upside I have access to all the major components, including 1 tonne tyres capable of providing enough inertia to do the job... then again human in a giant tennis ball launcher sound somewhat painful even when surrounded by a cage on a bike (for friction you know...)

how about a pneumatic cannon? plasma launcher? we already ruled out rail gun right? BTW: what are you planning?

what were those engines that the mythbusters used on the rocket car? it seems like that might work

100Kg? Rocket's? Your making some sort of missile aren't you? Fair play.

Ok maybe I'll make a missile since noone has a good rocket solution for me... then make myself a giant launcher and commit heinous acts of idiocy, I'm aiming for 0-62mph in under two seconds or the darwin awards.

You are only eligible for the Darwin Award if you either lose your reproductive capability due to your idiocy, or die.

not quite but weissensteinburg is a bit closer to the mark than you, he's not right though...


10 years ago

It depends strongly on the shape of the object. More information?

ummm me a bike and some rockets mostly, I don't really have a good guess for wind resistance so I jsut went with over estimates on weight etc to give some compensation..

You want to do 100km/h on a bicycle?? How big is your paper round??