The Planet Quiz Show

For Students:

If there was a bathtub big enough for Saturn to float in it, and then all of the water was drained from the tub, would there still be a ring left?

Saturn’s average density is about 0.7 grams per cubic centimeter. Matter floats when the buoyant force acting on an object is equal to or is greater than the weight of the object which is creating the displacement. Any quantity of matter with a density less than that of water (1 gram per cubic centimeter) will float in water because the buoyant force created by the displacement of the object exceeds the weight of the object. Density is equivalent to mass divided by volume. Even though the Titanic’s hull was built from steel that was about eight times denser than water, the total mass of the ship divided by its total volume (density) was still much less than one. Therefore, the Titanic floated. Once the hull was breached and became flooded, the Titanic’s density became greater than an equal volume of water, and the ship had to sink.

The planet Saturn is the jewel of the Solar System. NASA/JPL photo...