Comments on: Episode 120: Seesaw Saga

By: Raju

Raju — Thu, 19 Apr 2012 07:45:19 +0000

Three seconds is quite a long time, and the aricraft times were not too high either, according to the wikipedia article (about 30 seconds).I was quite skeptical of all the Hollywood movies depicting people jumping out of jet aricraft anyway. I remember seeing a program on discovery about a pilot who broke every blood vessel in his face by ejecting while supersonic.Another point which came to mind is that flight simulators might actually work (approximately). When a system is accelerated by a, the effective g forces will be $\\sqrt{a^2+g^2}$, and the simulator can give the actual direction, but not the magnitude by tilting the platform. I am not sure how effective it is really going to be as far as training goes, if your arm weighs 50 kg during a maneuver!

By: Enrico Martinez

Enrico Martinez — Wed, 21 Mar 2012 16:19:12 +0000

If the process was done correctly to propel the girl up to the 7th story building without sustaining any injury UPON the landing part procedure; WOULD the girl sustain any injury upon the immediate acceleration or force needed to propel her upwards WHEN SHE WAS ON the playground seesaw/catapult?

By: Thiagozequim

Thiagozequim — Sun, 29 Jan 2012 04:42:17 +0000

By: Thiagozequim

Thiagozequim — Sun, 29 Jan 2012 04:41:37 +0000

What is the name of the software that was used in the seesaw building simulation

By: cortjezter

cortjezter — Sat, 10 Sep 2011 01:20:27 +0000

i want to know why the girl was playing alone on a see-saw in the first place to even give a skydiver an open target to hit…

By: MSpears

MSpears — Thu, 25 Aug 2011 16:25:24 +0000

Actually, ‘normal’ seesaws haven’t been made out of wood in YEARS. Well, not the ones on playgrounds anyway, because we can’t have SPLINTERS in our children’s arses, can we?

(*rolls eyes* Builds character, I say. LET them get splinters.) LOL! Sorry, that was the kind of thing my uncle might’ve said.

Anyway, their ‘normal’ seesaw was made just like every other modern playground seesaw, out of metal.

By: MSpears

MSpears — Thu, 25 Aug 2011 16:19:38 +0000

They did try that. You must have missed it. A “normal” seesaw would just BEND under the impact. I’m sure SOMETHING would’ve happened to the girl, but flying 70 feet through the air? Nope.

By: Micheal T.

Micheal T. — Sun, 08 May 2011 16:59:31 +0000

they are engineered the same in Japan as they are here in the US.

By: Micheal T.

Micheal T. — Sun, 08 May 2011 02:16:20 +0000

v= velocity (meters/second)
Vo= initial velocity
a= acceleration
g= acceleration due to gravity (-9.8 m/s^2)
dx = change in distance (distance of acceleration, or delta x)

girl must travel apprx 21 meters in the y plane to reach 7 stories, assuming 10 ft (3.03M)/ story.

V^2=Vo^2+2g dx

-Vo^2=2(-9.8)21

Vo=20.3 m/s

Girl must have an initial velocity leaving the seesaw of 20.3 m/s in the y direction.
assuming the see saw is 1.5m from ground to apex,

V^2=Vo^2+2a dx

20.3^2=2*a*1.5

a=137m/s^2
girl must accelerate an average 137m/s^2 in the y direction over the 1.5m distance.

14g + 1g of gravity=
15g

humans have survived more than 45 g for short times, and 25 g up to 1.1 sec, which is more than enough time to accelerate the girl to the proper velocity.

a 16th G could account for enough velocity in the x direction to transport the girl to the nearest building roof.

F=Ma

20kg*157m/s^2=3136N

a force of 3136N (newtons) is required to acheive this acceleration.

sky diver’s velocity upon hitting ground 705.6 m/s
kinetic enerygy =
705.6^2= 2*a*1.5
165957.12m/s^2*90kg= 1.5×10^7N

1.5×10^7 N is more than enough to impart the required force on the girl. the elacticity of the seesaw would drastically reduce the rate at which energy is transferred to the girl down to something closer to what is required, and the ground would absorb the rest of the energy.

Assuming the seesaw was built properly to flex and deliver the required acceleration at a nearly constant rate (which is possible) the 16 Gs required are easily survivable by smaller children. This myth, according to the Physics and the math is Plausible.

By: Seneca

Seneca — Sun, 13 Mar 2011 20:20:40 +0000

I checked this website because I missed the last 10 minutes of the show and wanted to see if this was busted. I have to say the most entertaining part of all this is reading some of these posts…YGBSM Devedander et al, did y’all seriously spend hours composing posts about the merits of a mythical seesaw/skydiver test? Who cares?! It’s a freaking TV show! If you’re going to get yourself worked up about something, why not consider the national debt or the engineering of Japanese nuclear power plants.