They are a teaching aid for showing students how the various planets revolve and rotate. With an Earth/Moon/Sun system model you can answer all these questions by just turning the handle.. 1  Why we have day and night.  What a year is.
1. Static electricity is caused by the build up of electrical charges on the surface of objects, while current electricity is a phenomenon from the flow of electrons along a conductor. 2. When objects are rubbed, a loss and/or gain of electrons occurs, which results in the phenomenon of static electricity.
An example of this occurrence would be a person walking across the floor. Static electricity is generated as their shoe soles contact and separate from the floor surface. The amount of static electricity generated will increase due to the size of the sole surface, lower humidity and increased speed of movement.