A boat floating in a large pool is loaded with solid iron bars. The water level at the pool's edge is marked with a red line. The iron is now thrown overboard. When the water becomes calm again,
A) the red line is slightly lower than the water level.
B) the red line is slightly higher than the water level.
C) the red line is still at the water level.

Question

Quizplus · Accepted Answer

When the iron bars are in the boat, they displace a volume of water that weighs the same as the bars. When thrown overboard, they displace only their own volume, which is less than the volume they displaced when in the boat, because iron is denser than water. Therefore, the water level decreases.

A Boat Floating in a Large Pool Is Loaded with Solid