PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential
Problem
Three identical metallic blocks—A, B, and C—are mounted on separate insulating stands and arranged in a straight line with equal center-to-center separations that are large compared with the size of the blocks. Initially, all three blocks are electrically neutral. A technician performs the following sequence without ever allowing the blocks to touch each other:
(a) For each block, indicate whether its net charge is positive, negative, or zero immediately after Step 2. Support each determination with a detailed explanation that cites relevant physical principles.
(b) After Step 3, determine the net charge on blocks A and B. Clearly outline the reasoning path you use to reach your conclusion.
(c) Rank the magnitudes of the electrostatic forces experienced by block C due to blocks A and B after Step 4. Provide a complete justification that references charge magnitudes and separation distances.
(d) The technician claims that throughout the entire experiment the algebraic sum of the net charges on the three-block system remained constant. Construct an argument evaluating this claim, explicitly identifying each stage at which charge transfer did or did not occur.