
'Cause force equals MASS
times acceleration.
The Big Bang Theory Season 5, Episode 15

And, also, you don't account
for the missing MASS
The Big Bang Theory Season 11, Episode 10

Mass!
That's a cool nickname.
The Big Bang Theory Season 5, Episode 15

Trying to figure out why electrons
have no MASS...
The Big Bang Theory Season 3, Episode 14

That is an integrated ion trap
and time-of-flight MASS spectrometer.
The Big Bang Theory Season 6, Episode 5