Apparent weight is the normal force
The mistake
Treating scale reading and gravitational weight as always identical.
Why it feels right
A bathroom scale is used as a weight meter, so its reading feels like mg.
How to catch it
You answer mg for a scale in an accelerating elevator without applying Newton's second law.
The first principle
A scale reads the normal force. In an elevator accelerating upward, N - mg = ma, so N = m(g + a); accelerating downward gives N = m(g - a).
worked mini-example
A 60 kg student stands on a scale in an elevator accelerating upward at 2 m/s². What does the scale read?
Common wrong move
mg = 588 N.
Correct
N = m(g+a) = 60(11.8) = 708 N.
Test the repair NL-14 · transfer
include N
Make a fresh prediction before referring to the worked example.