The egg floats upwards in a stirred bottle of water due to the difference in density between the egg and the water. The egg is less dense than the water, so it experiences an upward buoyant force that causes it to float.
Initially, the egg sinks when placed in the water because it is denser than the water. The weight of the egg is greater than the buoyant force acting on it, causing it to sink.
Yes, the stirring motion is necessary for the egg to float. The motion of the water helps to distribute the egg's weight evenly, making it easier for the upward buoyant force to overcome the force of gravity and allow the egg to float.
If the stirring stops, the egg will eventually sink back to the bottom of the bottle. This is because the egg will settle into a position where the upward buoyant force is equal to the force of gravity, resulting in a state of equilibrium where the egg neither sinks nor floats.
Yes, any object that is less dense than water can float in a stirred bottle of water. This includes objects such as pieces of cork or plastic, which will also float upwards due to the difference in density between them and the water.