A piece of wood is floating in a tub of water. A second piece of wood rests on top of the first piece; it does NOT touch the wat
er. If the second piece of wood is removed from on top of the first piece and placed in the water, what happens to the water level in the tub? a. The water level cannot be determined without additional information. b. The water level drops. c. The water level remains unchanged. d. The water level rises.
The buoyancy and weight of the wood have to be equal for the system to be in equilibrium. The total mass (then, weight) of the wood is the same, so the total buoyancy has to be the same. Since buoyancy is the weight of the liquid displaced, the volume of liquid displaced will be the same in either case, which means that the water level will remain unchanged.
