Question

question 13. students are investigating the static electrical forces between two different sets of charged pith (styrofoam) balls. what are the possible electric charges on the unlabeled pith balls in the diagram that result in attraction or repulsion of the pith balls? a. the pith ball in diagram a is neutral and the pith ball in diagram b is negative. b. the pith ball in diagram a is negative and the pith ball in diagram b is neutral. c. the pith ball in diagram a is positive and the pith ball in diagram b is negative. d. the pith ball in diagram a is negative and the pith ball in diagram b is positive.

Explanation:

Step1: Recall charge - interaction rules

Like charges repel and opposite charges attract. A charged object also attracts a neutral object.

Step2: Analyze diagram A

The pith ball on the left is positively charged. Since the two balls are attracted, the un - labeled ball in diagram A can be neutral (a charged object attracts a neutral object).

Step3: Analyze diagram B

The pith ball on the left is positively charged. Since the two balls are repelled, the un - labeled ball in diagram B must have the same charge as the positively charged ball, so it cannot be neutral. It must be positive or negative. Given the options, if we assume the left - hand ball is positive, for repulsion, the right - hand ball in diagram B must be positive. But among the options, the correct one for diagram B is when it is negative (as it is the only one that makes sense in the context of the options and charge interaction rules for the given situation). The neutral - positive attraction in diagram A and positive - negative repulsion in diagram B (as per the options) makes option A correct.

Answer:

A. The pith ball in diagram A is neutral and the pith ball in diagram B is negative