Thermal equilibrium is when a hot and cold object (could also be air) come in contact with each other and over time become the same temperature.
thermal equilibrium is reached when both objects are the same temperature.
Answer:
c. V = k Q1 * Q2 / R1 potential energy of Q1 and Q2 separated by R
V2 / V1 = (R1 / R2) = 1/4
V2 = V1 / 4
