electrostatics the study of electric charges. the three subatomic particles – a review proton –...
TRANSCRIPT
The Three Subatomic Particles – A Review
Proton – Positive Charge (+), p+
Neutron – No Charge (0), n0
Electron – Negative Change (-), e-
In physics, “charge” is represented by the letter “q”
Electric Charges on Objects A charged object has an unequal
balance of positive and negative charges
Objects can be charged two ways… Positive (+), such as vinyl and rubber Negative (-), such as fur, glass, and
wool
How to Make a Charged Object(or, How to Transfer Charge)
Friction or Contact Rubbing two objects together, or even just
touching them, causes elctrons to move from the atoms of one object to the atoms of another object
Scuffing socks on the floor, rubbing a balloon on your hear, Swiffer dusters
Induction Electrons “jump” from one object to another
when they are brought in close contact, but do not touch
Using a charged balloon to raise the hairs on your arm, Van de Graaff generator
Properties of Charged Objects
Like charges repel, unlike (opposite) charges attract
Charges are not created, or destroyed – they are separated or combined (moved) Electrons added to, or removed from,
atoms Charges exert a force on other
charges over a distance
Because there’s a force, there are vectors
Electric force vectors show the Electric Field
ALWAYS point from (+) to (-) charges
For a single charge…
+ -
POSITIVE CHARGE NEGATIVE CHARGE
Magnets -Magnets have North and South poles
-If you break a magnet the broken pieces will still have North and South Poles
- Magnets produce magnetic fields that look similar to electrical fields
Conductors & Insulators Conductors allow charge to move easily
through them Metals
Insulators DO NOT allow charge to move easily through them Wood, Styrofoam
Materials usually exhibit the same property for heat transfer
The Unit of Charge Called a Coulomb (C) 1 Coulomb (C) has a charge equal to
6.25 x 1018 electrons Charge of 1 electron = -1.6 x 10-19 C
Units of Charge The coulomb is actually a very large
unit for static electricity. We need to use the metric prefixes
and scientific notation: 1 μC = 1 x 10-6 C (μ = “micro”) 1 nC = 1 x 10-9 C (n = “nano”) 1 pC = 1 x 10-12 C (p = “pico”)