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  1. David Thomson

    Free fall arrest

    im not sure. I think v0 is the velocity gained by fee fall, i.e. the velocity before deceleration starts? But i may be confused. Maybe the advisor will be back to sort it out?
  2. David Thomson

    Free fall arrest

    i got 0=1/2*10*3*3 -(54*3) +r0 so -r0 =45-150 so r0 =100 in round numbers
  3. David Thomson

    Medical Impossibility to have fever

    I think that 'fever' is caused by toxins from the virus affecting the hypothalamus glad. This causes malfunction of the body's thermostat which can result in elevated temperature and also shivering when the hypothalamus thinks body temperature is too high. Fortunately an elevated temperature...
  4. David Thomson

    Free fall arrest

    Hi, Yes. There would be a lot of design and testing involved. It has to go from snow-laden fir trees to something man made and reliable and suitable for 1000's of operations. Maybe I should look elsewhere in nature, sea anemones maybe?
  5. David Thomson

    Free fall arrest

    bungee jumping is a good alternative there are accidents tho, and its not so good for corporate events. I want 10 people leaping off the gantry together in evening wear and for it to be absolutely safe and foolproof by good design. i.e. test it with crash test dummys thrown in at all sorts of...
  6. David Thomson

    Free fall arrest

    I'm thinking that the decelerating ' stuff' is a circle about 30m in diameter absolutely stuffed with a construction of suitable material (doesn't have to be trees) so its homogeneous and you can enter it at any point. It has a tendency to upright you on the way down but does not matter if you...
  7. David Thomson

    Free fall arrest

    Thanks. In round numbers, assuming deceleration at 2g ( -20 m/s2) the stopping distance is 100m. in practice it would be best if this was non-linear, i.e. a slower start ramping up to 3g so the average would be 2g. In practice I think it would be better to enter the de-accleration zone at a...
  8. David Thomson

    Free fall arrest

    you are right, its a design issue. It would have to be designed such that someone diving in at any point in the canopy would be delivered safely to ground level. I think that may be possible if there is a circa 20m depth in which to bring the person to a stop. It would be fantastic to create...
  9. David Thomson

    Free fall arrest

    A fir tree is conical and displaces you increasingly away from the trunk as you descend, so after the initial impact on the most slender and flexible of twigs at the absolute top of the tree, you would be directed downwards and sideways towards the more flexible ends of each branch as you...
  10. David Thomson

    Free fall arrest

    Agreed, the canopy would have to work to arrest the fall if the impact was feet first or, like a diver, finger tips down. I think it is still possible to have a very dense system of artificial tree-like branches, twigs, leaves etc to catch all and slow down the movement. Bags of polystyrene...
  11. David Thomson

    Free fall arrest

    It is recorded that someone has survived a free-fall from an airplane by being lucky enough to land on snow-laden fir trees. My challenge is this: Create a mathematical model which describes the forces at play in order to determine the viability of creating a safe and fun 'thrill-seeker'...
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