Final answer:
The apple sinks in water due to its density being greater than that of water, while the beading effect on its surface is caused by water's surface tension. These principles relate to buoyancy and density but do not directly relate to predicting the motions of the Moon, which involves gravitational forces.
Step-by-step explanation:
The question involves a physical phenomenon, particularly related to the properties of water and the concept of buoyancy. When an apple sinks in water and looks fine, it signals that the density of the apple is greater than that of water, causing it to submerge. Yet, the fact that it looks fine suggests the water is not entering the apple, which could be due to a resistant outer layer.
Surface tension is another physical concept illustrated when water beads up on the surface of an apple. The cohesive forces between water molecules create a surface film that can support small weights and makes water droplets round on surfaces, as seen on the leaves and skin of the apple. While the sinking of an apple can be measured and described using physics principles, it is not directly related to predicting the motions of the Moon, which requires understanding gravitational forces on a much larger scale.
Understanding Buoyancy and Density
Buoyancy determines whether an object will sink or float in a fluid. It is a force exerted by the fluid that opposes an object's weight. If the object's density is less than the fluid's density, it will float; if it is more, it will sink. The apple sinking in water is a result of its density being greater than that of the water.