Since the elevator is accelerating downward, it represent the minus sign.
Step-by-step explanation:
- Acceleration is the rate of change of velocity concerning the time taken. It is a vector quantity since it depends on both magnitude and direction. If the elevator is moving in a downward direction, there are three cases it should follow whether the direction is positive (+) or negative (-).
- Case 1: An elevator is moving downwards with constant speed and there will be no acceleration or there will be zero acceleration.
- Case 2: An elevator is moving downwards and the speed increases, then it will be the negative direction and signifies a minus sign.
- Case 3: An elevator is moving downwards with a slow speed, then there will be a positive direction and it signifies a plus sign.
- When the elevator goes downward, our body scale will be in an upward direction and the gravitational force will be negative. Hence it represents a minus sign.