Physics 9 Flashcards
Static electricity
Electric charge that is collected and held in one place
What happens when two material are rubbed together
Depending on material one might lose and the other might gain electrons
What happens when electrons are rubbed off a material
The material becomes positively charged
What happens when a material gains electrons
It becomes negatively charged
Friction
Charging a material by rubbing
Uncharged material
Prior to being rubbed together - equal numbers of protons and electrons
Electrically neutral
Charged materials
If electrons are rubbed off protons stay behind and material is electrically charged, vice versa for losing protons
Laws of electric charge
Opposite charges attract
Like charges repel
Charged objects attract neutral objects
Static charge
Electric charge at rest
Electrostatics
Study of static charge
SI unit of electric charge
Coulomb (C)
Conduction
Charging when objects touch
Induction
Objects are charged without touching
Insulator
Substance where the electrons are so tightly bound to the atoms making up the material
Ex. Plastic
Conductors
Allow electrons to flow freely from one atom to another
Ex. metals
Semi conductors
Allow electrons to move, although there’s some resistance
Ec. Carbon, silicone
Current electricity
Electrical charge in motion
Source
Source of electrical energy
Conductor
Wire that electric current flows through
Load
Device that transforms electrical energy into other forms of energy
Switch
Device that can turn the circuit on/off
Ammeter
Used to measure electrical current in a circuit
Voltmeter
Used to measure the voltage in a circuit
Energy
The ability to do work
Potential energy
Stored energy that has the potential to make something move of change
Electric potential
Energy carried by elecric charges
Electrochemical cell
Battery that converts chemical energy into electric energy
Different in potential energy per coulomb of charge between two points of an electric circuit is
Voltage or potential difference
Kirchoff’s law
Vt = v1 + v2
Parallel circuit formla
Vt = v1 = v2
Voltage, resistance and current formulas
V = i x r r = v/i i = v/r
Power, voltage, time, resistance, energy, current formulas
v = p/i t = e/o e = p x t i = p / v p = v x i p = e / i
1000 mA
1 A
Electrochemical cell
Provides energy to push the negative charges through the conductors which are connected together
Dry cell
Moist paste-like substance and an electrolyte
Alkaline batteries
Wet cell
Solution is used as an electrolyte
Car batteries
Energy gormula
E = v x i x t E = p x t
1000 w
1 kw
3600s
1 h`
2 power formulas
p = v x i p = e / t
