Re: Physics Question

[Herbert H Gottlieb <herbgottlieb@JUNO.COM>]

On Fri, 06 Jun 2003 13:53:40 -0400 Frank Cardulla <ChemTchur@AOL.COM>
writes:
> Two identical feathered arrows are fired from two identical bows, on
> two identical planets (and make all other obvious assumptions).  Planet

> 1 has an atmopshere like Earth's.  Planet 2 has no atmosphere at all.
>
> I am assuming that the first arrow will basically flop end-over-end,
> since the feathers cannot affect the flight.

*** Your assumption sounds reasonable.
> But which arrow will fly further?  Will the "winner" depend on the
> angle of firing?  For example, if fired horizontally (and at reasonable

> speed-no going into orbit), will the feathers keep the arrow fired in
an atmosphere
> aloft sufficiently longer to compensate for air resistance so that it
will
> fly further? Or will air resistance make it fly less far?

*** I would expect that the initial speed of the arrow as well as its
initial
launching angle would both affect its range. I seriously doubt that the
absence of feathers would matter during flight in a vacuum.

> What about a 45% flight?

*** In the absence of air, an ititial launching at an angle of
45 degrees should provide the greatest range.
> Straight up?  Which would stay in the air longer?


*** In the absence of air, the arrow shot straight up would rise higher
and take a longer time to descend to the earth
> Can these questions be answered with reasonable confidence?

*** Yes. they can be answered with "reasonable" confidence. However,
I would not like to stake anyone's life on it. The topic
seems to be ideal for thorough scientific investigations by motivated
high school students. Hopefully several students in the country
will be challenged by their teachers to do so and report back to us
in a future phys-l contribution. In addition, the results of
such investigations can help students win fame and fortune in local
and national contests.

Herb Gottlieb  from New York City




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