An airplane heads north of east by 18 degrees for a distance of 67 km then heads due north for 39 km. What is the planes total displacement?

The plum pudding model of the atom states that ?

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

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?