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13-05-2005, 08:48 PM

The message
from (Nick Maclaren) contains these words:

Boggle. Hang a wooden ball of known weight on the end of a string,
shoot the pellet into it, and measure how far it swings; that gives
you the momentum.

No it doesn't, unless your piece of string is of infinite length.

Align the barrel with a spirit level, and measure
the dopy

The what?

of height with distance; that gives you the velocity.

I've no idea what you mean. To get the velocity you have to measure both
the distance and the time it takes for the pellet to travel that
distance.

Then you must allow for how much the pellet slows, or all you get is the
mean velocity over a distance, and the power of the gun must be measured
*AT* the muzzle, not halfway along any preselected distance.

Since the slowing of a pellet is not linear over a distance, and the
faster the pellet, the steeper the fall-off curve, you need to have a
much more reliable method.

The
mass can be measured with kitchen scales, and you can correct well
enough for air resistance (in the latter case, the former doesn't
need it) using 120 MPH as the terminal velocity of a tumbling human.

A (clothed) tumbling human doesn't have the smoothness of a pellet, nor
does it have the density, both of which have some bearing on the
terminal velocity.

I could probably think of several other methods if I put my mind to
it, but those should do as a start.

I think you might start with one which would work...

--
Rusty
Open the creaking gate to make a horrid.squeak, then lower the foobar.
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