That young Kirk finger grip! I gripe, because that turned me off to the trailer immediately, with a heavy Lurker groan.

With all the recent discoveries of “Extremeophiles” here on Earth, I can’t believe Planetary Scientists still say that a planet is “too cold, too hot, too high or low an atmospheric pressure, too much radiation (whatever) to support life.” Given what we’ve found here at home, I don’t think we can rationally rule anything out anymore as “Too extreme an environment” for life. We have found some microbes that can survive in the vaccum of space for God’s sake!

Kayla, another fabulous job! Thank you, as always, and congrats on making the AGU!

I must Segway off to my Jetpack now. };-D>

Fnet = Ffriction = µmg = ma

where the acceleration of the car is completely due to the friction force. M is the mass of the car, g is equal to the acceleration due to gravity (9.8m/s2) , µ is the coefficient of sliding friction between sand and tires (0.5 at most), and a is the acceleration of the car. Solving for a we get:

a = µg = (0.5)(9.8m/s2) = 4.9 m/s2

If we assume a relatively constant acceleration then

a = (v^2 – v0^2) / 2x

where v0 = 18m/s, a = – 4.9 m/s^2 and x = 30 m.

Solving for v we find that the car goes over the cliff at a speed v = 5.477 m/s.
——————————–

the POPSCI article gives Kirk a 4m/s difference because of his jumping but let’s give him only a tenth of that (the .477m/s.) And we’ll keep the 5 meter distance from the cliff.

——————————-
a = (v2 – v02)/2x = (0 – 5m/s)^2 / 2(5.0m) = 2.5 m/s^2

requiring a force of

Fnet = Ffingers = ma

and assuming that the young Kirk has a mass of around 50 kg we get

Ffingers = ma = (50kg)(2.5m/s^2) = 125 Newtons (or 28.1 pound-force)
———————————–
Doable (but I wouldn’t try it at home.) I still think other factors are not accounted for in this analysis but even they’re own methodology with a reasonable input yields a reasonable result. Of course a fair evaluation doesn’t generate as many hits :-)

PopSci assumes Jimmy Boy’s velocity when he hits the turf to be about 63 mph (v0 in the equation), when if you watch the trailer he is not traveling anywhere near that speed. Others are correct in pointing out that his body would have a much higher coefficient of friction than his fingers alone, so we can assume that his clothing and body were exerting much more force on the ground than his fingers were.

One can also see that as Kirk pitches over the edge of the cliff that he is still moving, therefore his final velocity (v2 in the equation) cannot be 0. He doesn’t come to a stop until he hangs over the edge, where all of his weight rests on his fingertips, which at this point don’t have to exert much more than 110 lbs of force to stop him.

Sorry, engineering student who had to put my two cents in