Charging on!1.2 & 1.3

Charging by Contact & Induction and Lightning

Pith ball electroscope Metal leaf electroscope

TVO VIDEO SERIES: http://www.youtube.com/watch?v=OL9wcTBjDN0&list=PLdIVKwXe8Up9z0pJGe0oLY5-yLbsaz_b7

Electroscope: detects the presence of electric charges

By Contact: ◦ Generating a charge on a neutral object by touching

it with a charged object Neutral object will have the same charge as the object

charging it

Charging...

Charging By Induction:

◦ Movement of electrons in a substance without direct contact with an object The force is attractive

Electric Fields

Attraction Repulsion

The space around a charged object The effect of its charge can be felt by other objects The greater the charge, the stronger (and bigger) the

field Electric forces are transmitted at the speed of light

Lightning!

Lightning!

Strong winds and collisions between water droplets and clouds cause electrons to be transferred and a charge to occur

Lower parts of clouds are negatively charged

Upper parts are positively charged

Lightning!

The large negative charge pushes away negative charges in the earth = Positive charge

Giant discharge = Lightning

heats air to 33000 degrees Celsius (hotter than sun)

Air molecules collide and produce thunder

Lightning!

A rod attached to a house that is connected to a buried cable or rod

If lightning strikes it will drain off into the ground without creating a fire in the house

Invented by Ben Franklin

Lightning Rods