RE: What's wrong with this?

From: Glenn Morton <>
Date: Mon Jun 21 2004 - 22:46:30 EDT

> Ted & Glenn -
> Not exactly. Objects in free fall _are_ weightless
> because in a coordinate frame moving with them the
> gravitational acceleration has been transformed away locally.
> It doesn't matter how high you are - you're weightless
> (except for the effects of air resistance) when you jump off
> the high dive. Astronauts train for weightlessness - or at
> least they used to - in planes that are in free fall (though
> perhaps moving upward & horizontally - on a parabolic path)
> for a fraction of a minute.

You are generalizing when we were speaking of the precise case you laid
out about the plane. We weren't speaking of high diving. We were talking
about a plane going quite fast, which would have a significant
frictional force. So, I will say that you are doing a bit of a bait and
switch here. Agreed that a diver is weightless (I used to do acrobatic
diving until I was 35 when I broke my leg in 4 places after landing on
the diving board after a beautiful (weightless) gainer).
Received on Mon Jun 21 23:03:37 2004

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