The apparatus commonly used in the laboratory to show expansion on heating is the ring andapparatus

ring and ball apparatus

Explanation:

In this experiment, the ball cannot pass through the ring due to its expansion, but the same ball can pass through the same ring when it is cooled down.

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.