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  • NARRATOR: Like Yasuhiro Kubo here, going for a Guinness

  • world record title.

  • He'll be free falling from around 10,000 feet

  • and attempting to catch up with his parachute

  • attached to this canister.

  • The record is determined by how long he waits before jumping.

  • At 50 seconds later, off he goes.

  • [music playing]

  • Well, that was a relief--

  • and a world record.

  • Free falling without a parachute is one of the most

  • dangerous stunts imaginable.

  • Do not even consider considering to consider to do it, ever.

  • Especially when even regular skydivers have their off days.

  • A little help please, bro?

  • Go on, you can do it.

  • Go on.

  • Great, thank you.

  • All right, so how does a skydiver fall fast enough

  • to catch up with a parachute thrown

  • out nearly a minute beforehand?

  • Well, to find out, we need to brush up on terminal

  • velocity and air resistance.

  • As an object falls, it collides with trillions

  • of tiny air molecules, resulting in air resistance.

  • As the object accelerates, the air resistance acting on it

  • increases until it matches the force of the object's weight.

  • It's now at terminal velocity, the maximum speed

  • it could fall.

  • A larger surface area increases air resistance,

  • and so decreases terminal velocity.

  • A smaller surface area decreases air resistance,

  • and so increases terminal velocity.

  • A skydiver in spread eagle position

  • hits terminal velocity around 120 miles an hour

  • after about 12 seconds.

  • But for Yasuhiro to catch up with his chute,

  • that is just too slow.

  • So which of our wannabe record breakers

  • has remembered how we speed up our terminal velocity?

  • Not these ones.

  • That is the complete opposite.

  • Their raft has a large surface area,

  • thereby increasing air resistance

  • and slowing them down.

  • OK, anyone else?

  • Yeah, that's it.

  • Going upside down and reducing his surface area

  • decreases air resistance and increases terminal velocity.

  • Trouble is-- oh, whoa, it's very hard to control.

  • Oh, that guy upside down, too?

  • Yes, he was.

  • Once he's caught up with his chute,

  • Yasuhiro needed to steer himself into position to grab it.

  • How did he do that?

  • Well, skydivers can also use air resistance to maneuver.

  • For example, by adjusting his body shape,

  • this guy deflects flex more air backwards,

  • which pushes him forwards.

  • Bullseye?

  • Somehow, all of our high flyers were fine,

  • but I think we should leave the record to Yasuhiro.

NARRATOR: Like Yasuhiro Kubo here, going for a Guinness

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