RadioBanter - View Single Post - Supporting theory that Antennas "Match" to 377 Ohms (Free space)

September 28th 03, 03:57 AM

(Richard Harrison) wrote in message ...
Dave Shrader wrote:
"If that assertion (I am 240 pounds "mass" on earth. That`s a fact. I am
240 pounds "mass" on moon. That`s a weird assertion!) is true, who
changed te density of the moon??"

Mass is the bulk of matter though not necessarily equal to its weight. A
mass weighing 240 pounds on earth weighs less on the moon because there
is less mutual attraction between the moon, of much smaller mass than
the earth`s mass, and the object which weighs 240 pounds on the earth.

Mass is the property which provides a body with inertia. Mass is the
mechanical analogy of inductance. Mass is equal to the weight of a body
divided by the acceleration due from gravity (32ft./sec./sec.). This is
an expression of Newton`s 2nd law of motion: F = MA, thus M = F/A.

Newton`s 1st law says that to move a body at rest, enough force must be
applied to overcome its inertia.

Newton`s 3rd law says that for every action there is an equal and
opposite reaction.

The gravitational force of the earth is stated as "1".

Not really; the standard acceleration due to gravity (more accurately,
of free fall), or an approximation of the local acceleration, is
sometimes expressed as 1 lb/lbf, or 1 kgf/kg, or 1 gee. But it isn't
dimensionless, and it is also often expressed with units in which its
numerical value is not one (always, if you are using SI units, the
modern metric system).

The gravitational
force on the moon is about 0.16 that on earth, so an object weighing 240
pounds on earth would weigh only 38.4 pounds on the moon.

That's certainly true enough, at least for one definition of weight.
But it has nothing to do with Dave Shrader's "I am 240 pounds "mass"
on moon. That`s a weird assertion!" You are talking about something
different from mass.

Gene Nygaard