|
| I understand that lots of people (including apparently the folks at
| NIST) want weight to be the same thing as gravitational
| force, but I have yet to hear one compelling reason for that.
|
"In science and technology, the weight of a body in a particular
reference frame is defined as the force that gives the body an
acceleration equal to the local acceleration of free fall in that
reference frame . . ."
Doesn't this say that the weight of an astronaught is zero in the rest
frame of the orbiting shuttle, since the local free-fall acceleration is
zero in that frame. Therefore the force to give it that acceleration is
zero, i.e. weightless??
"[6: ISO 31-3]. Thus the SI unit of the quantity weight defined in this
way is the newton (N). When the reference frame is a celestial object,
Earth for example, the weight of a body is commonly called the local
force of gravity on the body."