Part 2/6:
In examining buoyancy, let’s consider what occurs when an object is placed in a fluid. The object experiences two main forces: its weight (acting downward) and an upward buoyant force. The key idea is that the buoyant force acting on an object is equal to the weight of the fluid that the object displaces.
If you imagine placing an object in a body of water, the volume of water that is pushed aside corresponds to the submerged volume of the object, and the weight of this displaced water creates the buoyant force. Therefore, if the buoyant force is greater than the weight of the object, it will float; if it is less, the object will sink.