(a)[2]
Define the electric potential at a point.
(b(i))[1]
From Fig. 5.1, determine the sphere's radius.
(b(ii))[2]
From Fig. 5.1, determine the charge on the sphere.
(c(i))[2]
Two spheres are identical to the one in (b), and each carries the same charge as the sphere in (b). They are kept in a vacuum with their centres separated by $0.46\,\text{m}$. Assume that the charge on each sphere may be treated as a point charge at its centre. Calculate the electric potential energy $E_p$ of the two spheres.
(c(ii))[3]
The two spheres are now released at the same time so that they can move freely. Describe and explain how the spheres then move.