and it's not an arbitrary definition by the way, there are many formulas that, when derived properly, prove that mass is a constantly positive quantity, such as the classic equation E=mc^2 when it is manipulated in a more complex manner.
i'll try to spare the mumbo-jumbo and make it quick and simple:
physicists define mass as always positive, negative mass is nonexistent.
this is unless you get into theoretical physics involving hypothetical particles such as tachyons.
glass is classified as an amorphous solid.
to oversimplify:
solid - has definite shape and definite volume
liquid - no definite shape, but definite volume (ok, "slightly compressable")
gas - no definite shape, no definite volume
and yes there are more such as plasma, but these are the basic...
can anyone offer up some help? I've been working on this forever with no success.
On a frictionless surface, a 0.35 kg puck moves horizontally to the right (at an angle of 0°) and a speed of 2.3 m/s. It collides with a 0.23 kg puck that is stationary. After the collision, the puck that was...