Mass vs inertia

Don1 wrote:
KeithK wrote:
"Don1" wrote in message
oups.com...
Don1 wrote:
Mass is an unspecific body of matter. Inertia is the specific measure
of the force (f) exerted on, and/or by a body of matter, to the rate of
displacement (s/t) that it causes; where ft/s is a constant.

Mass is the specific measure of the impulse - the product of force (f)
and its duration (t) - exerted on, and/or by a body of matter, to the
rate of displacement (s/t) that it causes;

OK, that's better, although a bit unorthodox in viewpoint.
It's not usually stated that way, and it would be a tricky method
for measuring the numeric value of an object's mass, but the implied
equation works, assuming F is the force applied to an object of
mass M, T is the duration of the applied force, and s/t = V is the
object's resultant change in velocity:

It's usually written as the 'Impulse Equation':
F*T = M*V
where F*T is the Impulse applied to an object at rest, and M*V is the
resultant change in Momentum.

You write it your way; but I'll write it as ft=s/t; which makes it a
constant: Which is ft^2/s, for any given body, and is equal to 2w/g.

But I have to agree, one could conceivably determine an object's mass
by whacking it with a hammer, measuring how many microseconds
the whack lasted, and the average force, and observing it fly off the table.

It would be easier Keith, to just read the weight from a weight scale,
and divide that weight by g/2. That will determine the object's mass.


Don,

How do you calibrate your handy weight scale to read the correct lbf
force?

Most everyday scales are adjusted so that when you put 1 lbm on the
pan, it reads one.

But as a practical matter, how do you apply a standard force so that 1
lbf will read exactly 1 on the scale?

Double-A