The elevator is suspended with a spring scale on the ceiling, and a small ball is hung under the spring scale. When the elevator moves, the reading of the spring scale becomes larger Then why is the elevator moving downward to make uniform deceleration or upward to make uniform acceleration

The elevator is suspended with a spring scale on the ceiling, and a small ball is hung under the spring scale. When the elevator moves, the reading of the spring scale becomes larger Then why is the elevator moving downward to make uniform deceleration or upward to make uniform acceleration

When accelerating upward, the acceleration direction is upward. According to Newton's second law, f-mg = ma, f = Mg + Ma > mg, so the reading becomes larger
When decelerating downward, the acceleration direction is still upward
Therefore, the upward direction of acceleration is overweight. The downward direction of acceleration is weightlessness