sentences: potential energy of an object is determined by the mass and the height of the object & a roller coaster is a kind of object -> phenomenon matter of the tire clear is determined by its want and its width potential energy of the roller coaster is determined by its mass and its height  phenomenon matter of the tire clear is determined by its want and its width & the height of a roller coaster car is known -> if we know the mass of the roller coaster, then we can determine the potential energy of the rollar coaster