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  1. >the horizontal component of velocity does have an effect on the vertical component of drag and the vertical component of velocity does have an effect on the horizontal component of drag. nonsense,, tautology,, pseudoscience....your pick its like saying that if we have a triangle with sides a b c and we blow it up 2x the increase of length of a has an effect on length of c! thats bs,, no causality whatsoever,, the reason c became 2x is not because a or b became 2x, its because we blew the whole triangle up 2x! same here,, as pchapman perfectly explained, greater velocity = greater drag (in quadratic proportion), and its vertical component is greater than when the object is dropped with no horizontal speed total velocity is the primary thing, the cause of the effect,, not some mysterious crossbreeding btw horiz and vert components lol components r arbitrary imaginary things velocity is a real one u saying that horiz component of speed has "an effect" on vert comp of drag is like saying that the growing child became taller because the height from crotch to floor increased! lol
  2. I understand your feelings, though I disagree with the logic. If you would like to discuss this further we can do it in some other venue (at least not this thread). my logic is that its not ok to sell bullshit your prog fails an elementary bs check u disagree? its ok 4u to sell bs?!
  3. ***THANK U*** this is a perfect explanation even an idiot like me understood if only all physics professors were like u!
  4. The short answer is: the model is not perfect. The longer answer is, that there are multiple variables at play and the model must accommodate the steady state as well as the response to the inputs. This requires a compromise which results in parameters that produce overall behavior. By definition it is a mathematical approximation of the reality. As the model becomes better we'll see better results. thats very poor excuse the descent rates in no wind and in steady winds MUST match 100% ***or else*** u should ditch your 'model' completely u may not get simulation of control inputs or turns 100% right,,, nobody can,,, but not to match the descent rates is like writing a calculator program that when entered 2*2 gives 4.4. "yeah i know it must be 4 but my model is not perfect" "new version of my calculator will be better. 2*2 will be 4.2"
  5. we're talking about different things.. i didnt mean the quantitative difference between an object moving at 700mph and 20mph.. i meant qualitatative diff ok,,, one last try, more succinctly... two da vinci parachutes (essentially a round parachute with fully formed shape) r released from a balloon and from an airplane, from the same altitude simultaneously. which one will land first? my answer: the one dropped from the balloon this is the same answer, qualitatively, as with mythbusters bullet once u agree with that theres no reason not to agree that a round descends slightly slower through shear layers than still air your answer?
  6. >Not the same thing at all. And easily proved using regular Newtonian physics. how a bullet fired horizontally and a bullet dropped in the moving stream not the same thing? the result is the same.. it moves vertically slightly slower than bullet dropped in still medium >horizontal and vertical components of drag are no longer independent what do u mean independent? they r just projections of a vector, how they can be independent? >But format's thought experiment explicitly excluded shears. can u read b4 replying? when i finished with formats experiment, i introduced my own one, with shears.... reading comp probs? >Yep. Unfortunately it doesn't model the atmosphere. again can u read? i was talking about producing uniform stream in formats exp. it has nothing to do with the atmosphere, its a thought experiment!! i had F- in physics but even an idiot like me knows it better than "physics professor" hereby i demote u of your title and advise u to go to a middle school and start it from the ground up
  7. Ahh, the problem here is that a canopy's airpseed stays the same regardless of windspeed. The bullet analogy is more suited to a skydiver exiting a moving aeroplane compared to a balloon or a helicopter. In this case, the airspeeds are different, so descent rate is affected. true i was only answering format's thought experiment otoh... by analogy with this experiment, even a round parachute (with zero forward drive) will change its decent rate when going through shear layers, and it will float down always slightly slower regardless of whether u go from faster layer to slower or vice versa
  8. >Since you can't make a 2' deep pool with steady current of a viscous fluid that has the same speed all the way to the bottom sure u can just move the entire pool (with still water in it) boom! for the object dropped from above in it its tye perfectly steady current of viscous fluid or just drop the object in nonmoving still pool with same horizontal speed its relativity e = mc2 maybe u should take physics 101 mr "physics professor"
  9. the answer is "no" i vagely remember the episode of mythbusters where they proved that a bullet shot horizontally falls slower than just dropped
  10. >your thought experiment is rather meaningless because there's no way to test it. "there need be no intention of any kind to actually perform the experiment in question" physics professor, eh?
  11. +1 it would be even better if he wore a wingsuit
  12. i want 2 hear the correct def of g.r. from giselle martins in her teeny tinny micky mouse voice giselle where r u when we need u??!!!!!!!
  13. >I really can not see this being an illusion right after the canopy is fully inflated the jumper is walking left of canopy flight on the ground and the canopy starts deflating. and all 3 stood up their landings!!
  14. sky12345

    Cool airdrop

    i wonder if the do plf inside?
  15. not expanding an uncommon acronym on the 1st use is a sign of arrogance using a footnote sign without a corresponding footnote is a si gn of stupidity†