Which of the following is an example of convection?
the rays of the sun warming the earth
a hot oven warming the air around it
a hot object transferring heat to a cooler one
hot air rising and cooler air falling

Heena wants to measure the volume of a ball that is 24 cm across. how should she set up her equation?

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90

Most of the volume of an atom is occupied by the