260 likes | 436 Views
Physics . Electricity. Two Type of electricity. 1. Static Electricity. Electric charge that stays in one place. 2. Current Electricity. Moving electricity. What makes static electricity?. Recall the structure of the atom:. Negative charge (-). Neutral charge (0). Positive charge
E N D
Physics Electricity
Two Type of electricity 1. Static Electricity Electric charge that stays in one place 2. Current Electricity Moving electricity
What makes static electricity? Recall the structure of the atom: Negative charge (-) Neutral charge (0) Positive charge (+)
Charges balance each other to give a neutral charge to the atom Charge protons + + + 0 electrons - - -
When electrons are removed, the atom Becomes positive in charge Charge protons + + + +1 electrons - -
When electrons are added, the atom becomes negative in charge Charge protons + + + -1 electrons - - - -
Is this object positive or negative in charge? • + - + - + - + - + - + • + - + - + - + - + - • + - + - + - + - + - + • - + - + - + - + - + - Neutral
Is this object positive or negative in charge? • + - + - + + - + - + • + + + - + + - • + + - + + - + + Positive
Is this object positive or negative in charge? - + - + - + - + - + - + - - + - + - + - + - + - - + - + - + - + - + - + - Negative
Is this object positive or negative in charge? - + - + - - + - - + - - - - + - + - + - + - - Negative
Is this object positive or negative in charge? • + - + - + + + - + - + • + + + - + + - + Positive
An object becomes charged when electrons are either added or removed from it Protons are NEVER removed or added to make an object charged
Lawsof Static Charge 1. Opposite charges attract + + + + + + - - - - - - - -
Laws of Static Charge 2. Like charges repel + + + + + + + + + + + + - - - - - - - - - - - - - - - -
Laws of Static Charge 3. Charged objects attract neutral + + + + + + + - + - + - - - - - - - - - + - + - + -
Laws of Static Charge • Charged objects attract neutral- • here is what is really going on - - - + + + - - - - - - - - NOW this side is more positive and the two are attracted…
Laws of Static Charge • Charged objects attract neutral • here is what is really going on - - + + + + + + + - + + NOW this end is more negative and it attracts to the positive rod…
Two important points • Notice the protons DO NOT move – remember, they are in the center of the atoms so they do not move easily • Notice the neutral object is STILL neutral – the electrons are just moving around
Look again… • Charged objects attract neutral • here is what is going on - - + + + + + + + - + + See… still 3 + and 3 – and only the electrons move.
Creating Static Charge • Two methods of charging objects: • Induction • Conduction
Creating Static Charge Conduction– direct transfer of charge - electrons have been removed from an object due to friction. E.g. walking across a carpet and getting shocked body picks up electrons from carpet body negative touch a door and shock Why? because electrons in hand repel electrons in doorknob (+ charge) and e- from hand jump to knob electrical discharge SHOCK!!
Here is what happens in conduction Now this rod is positive + + + - - - - + + + - - And this rod is negative
Static electrical shock is this: Zap! - - + + + - - - Was negative, now is neutral