Solution
Related Formula
W = q₃ · Vsystem V = (kq₁)/(r₁) + (kq₂)/(r₂)Core Logic
Work done is equal to the potential energy acquired by the 3 nC charge in the electric field of the other two charges.
Step 1: Formula Setup
W = ( (kq₁)/( ) + (kq₂)/( ) ) q₃Step 2: Value Substitution
q₁ = 1 × 10⁻⁹ ~C q₂ = 2 × 10⁻⁹ ~C q₃ = 3 × 10⁻⁹ ~C = 3 × 10⁻² ~m W = 9 × 10⁹3 × 10⁻² ( 1 × 10⁻⁹ + 2 × 10⁻⁹ ) × 3 × 10⁻⁹Step 3: Final Calculation
W = 3 × 10¹¹ × 3 × 10⁻⁹ × 3 × 10⁻⁹ W = 27 × 10⁻⁷ ~J = 2.7 × 10⁻⁶ ~J = 2.7Pattern Recognition
Factor out common terms (k/) before substituting micro/nano orders to prevent simple arithmetic exponent errors.
Chapter Mix
Class 12 Physics: Electrostatic Potential and Capacitance