A thundercloud has the charge distribution illustrated above left. Treat this distribution as two point charges, a negative charge of -30C at a height of 2km above ground and a positive charge of +30 C at a height of 3km. The presence of these charges induces charges on the ground. Assuming the ground is a conductor, it can be shown that the induced charges can be treated as a charge of + 30 C at depth of 2km below ground and a charge -30 C at a depth of 3km, as shown above right. Consider P1, which is just above the ground directly below the thundercloud, and P2, which is 1km horizontally away from P1.
Determine the direction and magnitude of the electric field at point P1.
i. On the diagram above , clearly indicate the direction of the electric field at point P2.
ii. How does the magnitude of the field at this pont compare with the magnitude at point P1.
Greater Equal Less
Justify your answer.
(c) Letting the zero of potential be at infinity, determine the potential st these points
i. Point P1
ii. Point P2
a) Determine the electric potential at an altitude of 1km directly above point P1.
b) Determine the total electric potential energy of thisarrangement of charges.
