woodyapex

Nice one spyman ! thanks right! next question if i was going to pull something horizontally on a flat surface on a low friction trolly weighing 150 kg with 300kg of vertical downward gravity propelled force ? for now from stand still . ie a brick is tied to another brick and one is chucked of the ledge ! how fast will it pull the other off ?

Hi mac swell Firstly we are not brave just daft 2ndly your observations re tubalence wind direction and speed are all out of our hands so no use worrying too much about them so please ignore them . at the end of the day we all should have the same conditions so bad for us bad for them ! We are well aware speed is of the eccence , and my initial first questioin was " if 300 kg is dropped off a 6 m high platform how fast will it be travelling when it hits the ground ? could anyone please give me the answer ? If i get that? then i can get a base from there ! like i say i can put a 1:2 ratio on this i reckon and get a rough idea of how fast they were flying on the vid ? woody

Hi ya Great questions mp i'm going to try to answer them all . Firstly all the questions you asked have already been approached and thought about ! there is a 3 m capping on craft hieght not , maybe after a few teams starting from 8 m above the 6 m high platform as yes its def 6 m . So we have constructed a nice friction free as we can get trolley . so 8 m in total . I've watched nearly every flight i can and know the one you are on about with the " trip " we are not having any " trip " . just straight off . Our goal is to get as far as possible and not just land in the drink 8 m from the platform ( thats the main thing ) But we've gone in to try and win and even though there are lots of points available for aesthetics and a pre flight show we are not under any disillusions that the team that flies the futest has a better chance of winning Right Pilot Our pilot is on a strict diet at the min shedding pounds per the day ! He has never flown but today we have constructed a 40 meter runway . with a exit ramp at the end for test runs ! to test fly this plane / craft so we will learn to fly it for two weeks before the big day ! there has been some calculations put into this craft so far and we are using a wing shape designed by the guy whom designed the airbus A 380 so a trusted wing foil. as for ground effect i am very familiar with it but would rather make this as fail proof as possible , as the plane that over compensated was a slightly differently engineered craft ( maybe stronger ) ours has to look like a kestrel lol and in a ideal way not a plane . hard i know but we will get great points if it looks like our initial design. YouTube - red bull flugtag locarno switzerland winner team 2006 balu The above link altough looking like a plane is what we'd love to achive on the day in style and distance . take not how the plane only benefits on the last metre 2 metre of there plunge hence why we'd like to up the anti . Let me know what you think ! thanks woody

ok Mooey sorry for the delay been mad busy building the plane !! right this it top secret ( seriously ) ok we have a 8 m wide plane we need to launch off a 6 m high platform ! to get the lift and speed we need to achieve at least 20 mph ! But faster means further ! any less we go down hill we are aiming to have the craft and pilot weighing no more then 150 kg although ideally less . weight is downward force but speed is a squared measurement so speed is better then less weight but both is really good though ( leave the weight to us ) So back to speed . ok so bearing in mind plane and pilot aprox 150 kg we the pullers 300 kg ish ( macdonalds every day ) i say pullers as we are going to pull it off the pier . so lets say we can get to ( and we are about to do tests ) 15 mph then jump off ! For a split second we will add nothing to the speed of the craft as we are free falling and can not unfortunatly jump down hill then we will eventaully hit 15 mph heading down hill and that will give us extra speed , now obviously thats why i'd like to know the answer to the oririnal question how fast would we be travelling after falling 6 m ?? i realize drag will have effect and friction on rope ect but at the min im thinking ideal situation ! i hope your all still with me !?? right now we have a little potential trick up our sleeve to use a 1:2 pull ratio so 300 kg pulling 150 kg but as it turns out that will make us be pulling the same as we weigh ! Now the amount we can pull is undefined at the min ! as we don't know how strong we are and of cause you dont ! but what should be simpler is the calculation after we jump off still pulling 1:2 but obvioulsey the speed we were travelling at leaving ramp would have to be taken into account ! ie 10 mph take off speed ( tos ) on jumping should pull 14 mph on landing and 12 mph tos should pul 16 mph on landing !! Friction is going to play a big part on our efficency but again leave that to us ! so lets ignore that if we can ! Yes i know what you are thinking! it is the r e d b u l l F l u g t a g we are in but please don't retype that as i really don't want it to show in google searches Thanks a lot guys and girls and i'm sure you mooey will put this problem / puzzle in the right place in this forum and you have my total perrmision to cut and paste into a new topic if needed ( will you just let me know where so i can find it ) Hope you can help thanks woody

Mooey poo I have got to be honest there is a hell of a lot more to this then what ive put ! it is for a spcific event ive entered and besides the little problem ive put there is also a lot of wind drag ! now the long and short of it ive got to design a plane , build a plane ! got to talk to the press , sort out sponsorship , communicate with sponsors ,make a video diary ! oh and did i mention build a 8m long and wide plane ? I realize how your forum works now , but did not initially ! for the sake of a probably 10 second calculation i presumed one of your forum members may just work it out . and i'm sure they would ! I read how the " homework " forum works thats why i put it into the physics forum ! Don't worry about it as im sure you wont ill sort it out but i just don't have the time and at the min brain space to start from scratch on this subject ! thanks woody

the formulas are losing me a little as its chuffing ages since i did them at school ! i realize it will take .62 of a second i think ?? to hit the ground but where do i put that in the formula ?

9.8m per second ? sato what about excelaration or have you factored that in ? im looking for the speed its doing when it hits the ground ? is it still 9.8 m per second ? thanks

Im sure this is a simple calculation but ! An object weighing 300 kg is dropped off a ledge 6 m high ! how fast would it be travelling when it hits the ground ? i realize weight at this point is not too much of a issue but when i get an answer to this , i weight will be for my next question! Thanks in advance !