Science 2

Static electricity occurs when two surfaces rub together, and electrons from one surface move to the other, generating a net negative charge. When this negatively charged surface comes in contact with a conductor, the electrons jump from this surface to the conductor, and can be seen as a static spark.

Two students examined the effect of air humidity and static spark production.

Experiment 1

The students first rubbed the surfaces of various materials together for 3 minutes at a constant air humidity, and counted the number of visible static sparks. The procedure was repeated three times, and the averages were calculated and are presented in Table 1. The results are summarized below.

Experiment 2

To test the effect of humidity on static shock production, the students rubbed a balloon with a cloth for a given length of time. At the end of the time interval, the balloons were held against a wire that lead to a voltmeter to measure the output of electricity. The results are summarized in Table 2.