Certainly! Let's break it down step by step to explain the sensations felt in each situation:
1. As the elevator begins to descend:
- Sketch: Draw an elevator moving downwards.
- Explanation: When the elevator starts descending, you momentarily feel lighter. This sensation occurs because as the elevator accelerates downward, you and the elevator are both accelerating in the same direction. The force of gravity acting on you is still present, but it is momentarily slightly less than your normal weight due to the acceleration of the elevator downward. This results in you feeling lighter for a brief moment.
2. As the elevator begins to stop:
- Sketch: Draw an elevator coming to a stop.
- Explanation: When the elevator starts decelerating to come to a stop, you momentarily feel heavier. As the elevator slows down, the force of gravity acting on you remains constant, but now there is an additional force acting on you in the opposite direction of the elevator's motion (upward deceleration force). This momentarily increases the effective force pushing you against the elevator floor, making you feel heavier for a brief moment.
In both scenarios, it's essential to consider the interplay of gravitational force, acceleration, and deceleration to understand the changing sensations experienced inside the elevator.