Mass and weight

ErnieM

Joined Apr 24, 2011
8,377
Sometimes in the interest of not annoying the unwashed masses we who know use simple terms to describe things that are not quite correct technically. Weight and mass being one of these. My mom would have no idea what mass is but knows what weight means. As she doesn't do physics and will never hover in orbit in a zero G environment she has no need for the entire concept of mass.

There's no need to confuse her. "We" know the difference and that's the important thing. Excepting...


Mmmmm... M&M's:

Now THAT'S important!
 

Markd77

Joined Sep 7, 2009
2,806
Just to be super pedantic, even a balance scale doesn't measure mass perfectly because of buoyancy effects. A block of expanded polystyrene with a mass of 1kg will measure less on the scale than a block of lead with the same mass. For an extreme example try to measure the mass of a helium filled balloon.
 

someonesdad

Joined Jul 7, 2009
1,583
Absolutely correct about buoyancy -- that's why all the experimental books from 100 years ago showed you have to correct for it. Few people outside of analytical chemists, etc. are aware of it today...
 

Wendy

Joined Mar 24, 2008
23,415
Wonder how a spinning space station will affect the measurements? It isn't real gravity, and there is the Coriolis Force to consider.
 
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