Why is buoyancy related to density?

The other people answered the question well, so I would add some additional points. The fundamental reason why buoyancy appears is the pressure of water. Consider a enclosed space filled with water. read more

The fundamental reason why buoyancy appears is the pressure of water. Consider a enclosed space filled with water. The gravitational force acting to the water inside this enclosed space would be perfectly equal to the pressure the surrounding waters acts upon the water-filled space, as the water must be stationary. read more

Buoyancy is the upward force caused by a fluid, such as water. This concept helps to explain why some things float while other objects sink. Buoyancy is an important factor in the design of many objects and in a number of water-based activities, such as boating or scuba diving. read more