A7 kg box slides down a long, frictionless incline of angle 28° . it starts from rest at time t = 0 at the top of the incline at a height 27 m above the ground. what is the original potential energy of the box relative to the ground? the acceleration due to gravity is 9.81 m/s 2 . answer in units of j.

Write the correct abbreviation for each metric unit

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 element x has 99 protons how many electrons does it have