> >The Case
> >--------
> >James Bond is in an airplane over the Atlantic Ocean; the plane is flying
> >at an altitude of 8,000 meters above sea level. James jumps out to land
on
> >a small island, but unfortunately his parachute fails (d'oh!). For 007,
> >this means 8,000 meters of free fall before he plunges into the ocean.
> >
> Well, it's not _free fall_, because the resistance of the air slows him
down.
Still free fall. If you're falling without an aid designed to arrest that
fall, it's free fall. Falling at terminal velocity in air is still free
fall. Free fall in orbit is only different because you're missing the
ground.... (Very Douglas Adams thought there...).
> >The Questions
> >-------------
> >1. What is James' speed (in meters per second) when he hits the water?
You
> >may assume that his initial speed (at the moment he leaves the airplane)
is
> >0.00 meters per second.
> >
> Not enough data. He will be in the terminal speed [there's no way he would
> be falling with free fall's supersonic speed of sqrt(2 g h) = 400 m/s],
but
> the calculation of the terminal speed depends on his arm/leg position, and
> on many other factors, like his clothes, etc.
Approximately 120mph (190kph), IIRC. So, 53m/s, very approximately.
> >2. Once James is under water, the water will slow him down. At how many
> >meters below the surface will his speed reach 0.00 m/s?
> >
> Again, not enough data - but he would probably sink forever. AFAIK, the
> density of a living human being is bigger than the density of water.
Which is why you bob to the surface when you dive into a swimming pool...
Think about it Alberto. We're 70% Water. A lot of the rest is fat and air
spaces....
Well, water is 25 times as dense as air? (Guessing completely...), so root25
times the amount of force needed to maintain TV in air, which would
mean -50m/s/s, so about a second to stop. Splat. :o) And yes, I was making
that up as I went alomg, but it's convincing, no? ;o)
> BTW, this is not a _Math_ Challenge, this is a Physics Challenge :-)
>
> Alberto Monteiro
Everything is maths eventually...
Cgharlie
