Answer to Question #331613 in Electricity and Magnetism for Xena

Question

Experiment 1

Materials: salt, fine pepper, small dish, plastic comb, wool/cotton cloth.

Procedure:

1. Put the salt and fine pepper separately in a small dish

2. Rub the plastic comb with cloth repeatedly.

3. Hover the comb over the salt and fine pepper.

Questions:

1. What do you think is the charge of the salt and fine pepper in step 1?

2. What do you think is the charge of the comb in step 2?

3. explain what happened in the experiment.

Answer 1

1. Almost all bodies around us are neutral, unless some specific actions were made to make them charged. Thus, the charge of the salt and pepper is zero.

2. The charge of the plastic comb rubbed with cloth is negative.

3. In the experiment pepper is attracted to the comb, unlike the salt. This happens because the pepper can be polarized by the electrons in the comb easily, compared to the salt. Thus, the comp attracts these polarization charges. Beside, the pepper is lighter, thus move more freely.