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AP® Physics 1 & 2

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Moderate

Experiment Analysis - Fundamental Law

APPH12-M142BK

Two students conduct the following experiments and come to different conclusions.

Experiment 1: Student A rubs a glass rod with silk then hangs the glass rod by a string. The end of the rod attracts a plastic rod that is rubbed with fur.

Experiment 2: Student B rubs a glass rod with silk then hangs the glass rod by a string. The end of the rod repels a second glass rod that is also rubbed with silk. Student A hypothesizes that there are two kinds of electricity.

Student A reasons that friction between some types of objects produce positive electricity while friction between other types of objects produce negative electricity.

Student B hypothesizes that there is just one type of electricity. Student B reasons that neutral objects have equal amounts of positive and negative electricity, and that friction between neutral objects will separate the positive from the negative.

Student B’s hypothesis is a restatement of which fundamental physics law?

A

Energy Conservation

B

Charge Conservation

C

Action / Reaction

D

Equal Areas in Equal Times