"Buoyancy, is the ability to float. As you may know, when something appears to be hollow, it floats. When something is solid, it sinks. Can anyone tell me why this is?" Professor Sellscope asked.
Alexis immediatley raised her hand, trying to make a good first impression.
"Yes, miss Alexis." Sellscope nodded to the girl.
"If an object is solid, all of the weight, from the outside in, creates a power, followed by the pull of gravity, which sinks it down. However, when an object is hollow, there is no inner weight, and all the weight goes to the outside of the object, balancing weight on both sides, which keeps the object from sinking." Alexis explained, looking at the Professor the whole time.
Sellscope nodded.
"Now, buoyancy doesn't always work that way. Take a barbie doll for example. This American object is solid, most of the time, but it still floats. Can anyone tell me why this is?" Professor Sellscope asked.
Alexis didn't raise her hand, because unfortunately, she didn't know the answer.