What is the Electricity ?

-Electricity caused by electrons move.

- Electric charge consist of positive charge (proton) and negative charge ( electron)

- Static electricity is an electric charge that does not flow or an electricity the electric charge of which lies at rest condition.

What is the Electric charge?

ELECTRICITY

STATIC ELECTRICITY

Why her hair can be pulled by the balloon?

-Electrons move from the hair to the balloon

-So the balloon more electron or negatively charged, and the hair loses electron or positively charged

-Static electricity is the accumulation of electric charges in an object.

What is the Static Electricity?

Why the paper stick can be pulled by Your comb ?

-Electrons move from the hair to the comb - The comb more electron or negatively charged, and the hair loses electron or positively charged-So the comb can be pull of paper stick

Rub the comb to your hair, then it close to the paper.

SAFE DISCHARGING

A B C

Neutral cloudsClouds with polaried charges A lightning strike

When lightning strikes, the discharging of electrostatic charges from the lower part of clouds to the ground will flow through this lightning conductor. Electric charges will flow to the ground safety through the metal wire and into the ground.

Have you ever seen lightning when it is raining? What causes lightning?

DISCHARGING ELECTRIC CHARGES

Electrosstatic discharge is a sudden flash of electric charges occurs when electric charges move together at the same time.Static discharging is the movement of electrostatic charge from one object to another.Thunder is the discharging of electrostatic charges in the air can create a great noise.

ELECTROSCOPE

metalAn electroskop which is charged at first can be usedTo determine the kind of charge that is transferred

If a positively charged object is brought closer to the electroscopeElectrons inducted upward , so that both electroscope leaves willBe widely separated.

COULOMB’S LAW

Why the both balloons repel each other?

The interaction between two electrically charged objects

The same kind of charges will repel, while different kind will Attract each other

1. The Magnitude of Force between charge qA and qB, is directly proportional to the number of both charges

. The Magnitude of Force between charge qA and qB, is inversely proportional to the square distance (r) between them.

F = 1/r2

F = q1.q2

2

In mathematics we can say

F ≈ qA . qB

r2F =k. qA . qB

r2

Note : k = 9x109 Nm2/C2. q = Charge (C) F = Force ( N) r = distance (m)