Final answer:
Rubbing John Travoltage's foot against the carpet causes electrons to transfer to his foot, negatively charging him and positively charging the carpet due to electron loss, demonstrating the triboelectric effect and conservation of charge.
Step-by-step explanation:
When John Travoltage rubs his foot on the carpet, electrons are transferred from the carpet to his foot. This results in John acquiring a negative charge, due to the excess of electrons. Consequently, the carpet becomes positively charged, as it now has a deficiency of electrons. This is a common example of charging by contact and the phenomenon where rubbing two materials together causes electrons to be transferred from one to the other is known as triboelectric effect.
It's important to note that the net charge of the system remains constant due to the conservation of charge. The carpet lost electrons, which are negatively charged particles, and thus attained a positive charge. If John then touches a metallic object like a doorknob, he may experience a shock as the excess electrons are discharged, returning him to an electrically neutral state.
This entire process demonstrates the polarization of charges and how electric charge can be transferred between objects, maintaining the overall balance of charge within a closed system.