Try at least 2 of the 3 techniques to examine the relationship of distance to magnetic force. Measure at least 5 distances for each. Keep good records of your methods and results. Make two graphs showing the relationship. http://rfrazier.msblogs.aes.ac.in/2015/04/22/22-april-science-7-how-does-distance-affect-the-size-of-the-magnetic-force/
Positive and Negative
Defined: When a glass rod is rubbed with silk, the glass becomes positively charged.
When a rubber rod is rubbed with wool, the rubber becomes negatively charged.
Try the following simulations: