Which of the following equations are dimensionally correct? (a) vf= vi+ax (b) y 5 (2 m) cos (kx), where k 5 2 m21 The mass of a copper atom is 1.06 3 10225 kg, and the density of copper is kg/m3 . (a) Determine the number of atoms in cm3 of copper. (b) Visualize the one cubic centimeter as formed by stacking up identical cubes, with one copper atom at the center of each. Determine the volume of each cube. (c) Find the edge dimension of each cube, which represents an estimate for the spacing between atoms.