Buoyancy: A piece of wood is floating in a bathtub. A second piece of wood sits on top of the first piece, and does not touch the water. If the top piece is taken off and placed in the water, what happens to the water level in the tub?
A) It goes up.
B) It goes down.
C) It does not change.
D) This cannot be determined without knowing the volume of the top piece of wood.

Question

Quizplus · Accepted Answer

The overall volume of the wood in the tub has not changed, so the water level will remain the same. The displaced water volume from the first piece of wood is already filling the space that the second piece of wood will occupy when placed in the water.

Buoyancy: a Piece of Wood Is Floating in a Bathtub