The ancient greeks believed earth was at the center of the universe. true or false?

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star

An object's buoyant force and weight mean the same thing.a. trueb. false

In a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. what should be the radius of curvature of the cornea such that the image of an object 40.0 cm from the cornea’s vertex is focused on the retina?