At some automobile toll booths, a thin metal wire protrudes from the road, making contact with cars before they reach the toll collector. What is the purpose of this wire?
Solution 9E Step 1 of 2 : Static electricity is produced when two materials rub against each other, causing a buildup of electrical charges. All materials are made up of negatively- and positively-charged particles. These usually exist in equal amounts, balancing each other out. But when two materials come into contact, one may ‘steal’ negatively-charged electrons from the other. One material ends up with more negative charges than positive ones, meaning that it becomes negatively-charged overall, whilst the other becomes positively-charged. If the charges cannot move away as they are produced, they accumulate in the material as static charge, or electricity.