1. When a ping-pong ball is placed at the bottom of an inverted水瓶 and water is poured into it, the ball does not float to the surface immediately.
2. This is because the contact area between the ball and the water is relatively small, resulting in an insufficient buoyant force to lift the ball.
3. To observe this phenomenon, you can first cut off the bottom of a plastic bottle, place the ping-pong ball inside, and then continue to fill it with water.
4. In a fully enclosed environment, the ping-pong ball remains at the bottom due to the lack of adequate buoyant force (buoyant force is the pressure difference between the top and bottom surfaces of the liquid).
5. According to Archimedes' principle, the buoyant force on an object in a fluid is equal to the weight of the fluid it displaces. When the buoyant force equals the weight of the object, the object will float.
6. In the experiment, when water is poured into the bottle, if the water level is low, the ping-pong ball and the bottle create a near-sealed space. At this point, the pressure difference is not significant, and the ball will not float.
7. As the amount of water increases, the buoyant force gradually exceeds the weight of the ping-pong ball, causing it to float out of the bottle opening.
8. During the experiment, care must be taken to control the rate of water flow to observe the ball's floating and sinking state under different pressure differences.
