Compare how your weight, mass, and the normal force exerted by the floor change when you are in an elevator that starts from rest and accelerates upward.

Answer 1

F = m A

when at rest.
Force down on floor =weight = m g
Force up from floor on shoes = m g
Force up - Force down = 0 so A = 0

when accelerating upward the force up from floor on shoes must be greater thsn the force down, m g

Fup - m g = m A
so
Fup = m g + m A