Answer: v2 = 4.5v
Explanation: The potential difference (v) and distance (r) from any arbitrary point have an inverse relationship.
That's voltage is inversely proportional to distance.
v = k/r
Hence, we have that
v1 * r1 = v2 * r2
v1 = 9v, r1 = 1m, v2=?, r2 = 2m
9 * 1 = v2 * 2
9 = 2 * v2
v2 = 9/2
v2 = 4.5v