Answer:
q = 0.1086 micro Coulombs
Explanation:
By Coulombs law, we have;
Where;
F = The electric force = 120 mgm
q₁ and q₂ = Charge
r = The separating distance = 30 cm = 0.3 m
k = 8.9876×10⁹ kg·m³/(s²·C²)
Where, q₁ and q₂, we have;
Whereby the force is the force of 120 milligram mass, we have;
0.00012 × 9.81 = 000011772 N
Substituting the values, we have;
q = 0.1086 micro Coulombs.