Triboelectric Effect & Charge

Electrostatics Triboelectric Effect & Charge: Triboelectric Effect is a type of contact electrification on which certain materials become electrically charged after they are separated from a different material with which they were in contact The charge of a proton/electron is 1.6x10-19 C (just opposite magnitude for a proton vs. an electron) Coulomb’s Law: Coulomb’s Law describes the electric force between two charges: 𝐹! = His law is very similar to Newton’s Law of Gravity which is: 𝐹& = "|$1 $2 | %2 &'1 '2 %2 The electrostatic force occurs at a much smaller scale than the gravitational force, also gravity does not repel like electrostatic forces can The electrostatic constant k is approximately 9x109 Nm2/C2 (in order to make sure Newtons are left over) Conservation of Charge: As long as no charge enters or leaves a closed space, then the charge within that area will be remain constant even if they come together and convert to other things This law works even in principles such as decay and the likes Conductors & Insulators: Although not 100% true, you can basically boil down materials into two categories: conductors and insulators In both solids, the positively charged nucleus does not move, but electrons in conductors can move around freely and not in insulators The electrons don’t move freely, you need to generate some sort of electric field If you set up an insulator to a battery, the electrons and protons can shift, even though they don’t necessarily move If you add extra electrons (charge) to a conductor, the electrons will migrate to the furthest edge in order to get as far away from one another as possible Also, taking away electrons is sort of like adding a positive Examples of insulators: glass, wood, plastics, etc Examples of conductors: gold, copper, silver (basically the metals) Charge by induction occurs when charged rod approaches a non charged rod and therefore end up having positive and negative charges attracting the two rods (don’t touch physically though) → connect to a ground which will give the second rod a net charge (cut the ground and therefore keep the net charge on the new rod) - Electric Field: Fe/q = kQ/r2 = E (just a manipulation of Coulomb’s Law) → Electric Field is in units of N/C Therefore, Fe = Eq The electric field lines radiate outward from a point charge (higher the density the stronger the field) and they never cross The direction of the field lines has to do with the direction a positively charged particles would move if placed within the electric field Electric Potential: Electric potential energy is the energy that is needed to move a charge against an electric field (work done to get it somewhere) Electric Potential (Voltage) is the difference in potential energy per unit charge between two locations in an electric field (J/C) and is therefore independent of the size of the particle (find this in Voltage video if you need further explanation) PEe = Ue = qV → this is because you need to cancel out the coulomb value to get back to potential energy) V = kQ/r so therefore Ue = (kQq)/R (Big Q is what is generating the electrical field and little q is what is being placed into the field!) Also, voltage is the DIFFERENCE in electric potentials and can be referred to in units of volts Electric Potential Energy: Remember, W = Fd which can be also be expressed as W = (Eq)d Mass of a proton is 6.67x10-27 kg Mass of an electron is 9.1x10-31 kg `