Well, you could get the mass as
ad then
, where
is the sea level weight,
the sea level accel.,
the accel. above while
the weight above.
Characteristic properties are used because the sample size and the shape of the substance does not matter.
When heated, particles vibrate faster, thus increasing the distance between one another. The distance between these particles results in changes of state. Therefore, increased molecular motion results in expansion of an object. This works vice versa for cooling. As the vibrations slow down, the particles become closer together. This results in contraction.
