Re: Feeling Acceleration

[jmclean@chem.ucsd.edu (James Mclean)]

Donald E. Simanek says:
> Almost all of our measuring instruments measure a secondary effect of the
> thing we claim to be measuring.

Donald certainly makes a good point.

Nonetheless:
The accelerometer in and auto air bag measures the auto's acceleration
   without measuring the force on the auto.  If the auto's mass were known,
   then the device could subsequently figure the force.
A spring scale will measure the force between two bodies, but doesn't give
   any indication as to whether either body is accelerating.  But given
   additional information, an acceleration could be deduced.

Some measurements are more indirect than others.

-- 
--James McLean
jmclean@chem.ucsd.edu
post doc
UC San Diego, Chemistry