Q: Can you please explain how a ship made out of iron and steel can float?

—Richard Morris, Newnan

A: Greek mathematician Archimedes came up with a principle that states that "in order for an object to float, (the) object must be able to displace the amount (of) water equal to its own weight," according to scienceline.ucsb.edu, a University of California Santa Barbara website. The displaced water wants to go back to where it was, or displaced from, so it forces the object upward. This is called the buoyant force.

If the object doesn’t displace the correct amount of water or fluid, it will sink. The shape of the object also is crucial to buoyancy, so ships are designed with hulls specific to its size and shape. “A ship’s density has to include all the weight in the entire volume of the ship,” which includes air. The total density is less than water, which helps allow the ship to float.

Q: Where is Elisabeth Hasselbeck of “Fox & Friends?” She hasn’t been on for four weeks.

—Mary Edwards, Griffin

A: Hasselbeck recently had surgery that requires her to take some time off from the show. Co-host Steve Doocy told viewers on Oct. 16 that Hasselbeck would "be out for a couple of weeks." Hasselbeck hasn't tweeted since Oct. 10 and a show spokesperson told the Wrap: "Elisabeth has asked for all to respect her wishes for privacy in regards to further details at this time."

Andy Johnston wrote this column. Do you have a question about the news? We’ll try to get the answer. Call 404-222-2002 or email q&a@ajc.com (include name, phone and city).