Electric charge is a fundamental property of matter, like mass. Electric charge is a fundamental property of matter, like mass. Objects are either positive,

Electric Charge and Force

Electric Charge

• Electric charge is a fundamental property of matter, like mass.

• Objects are either positive, negative, or neutral.

• Like charges repel, opposite charges attract.

Electric Charge

• Charges come from within the atom.–Protons = positive– Electrons = negative

• Electric charges depends on an imbalance of protons and electrons

Electric Charge

p – e = charge(# of p+ – # e- = net

charge)

Electric Charge

• The unit of electric charge is the coulomb (C).–Charge for both p+ and e- = 1.6 x 10-19 C

Transfer of Electric Charge• Electrical forces cause electrons to move, or

flow.–Electricity is flowing electrons.

• Conductors allow electricity to flow.–Metals tend to be excellent conductors.

• Insulators resist the flow of electricity.

Transfer of Electric Charge

• Objects can be charged by:1. Frictiono Moving an object

against another can transfer electrons from one to the other

o Example: rubbing balloon on your hair.

2. Contact

Transfer of Electric Charge

• Objects can be charged by:1. Friction2. Contacto Touching a charged object to an

uncharged object can transfer electrons.o Example: Shock from touching door

knob after rubbing feet on carpet.

Transfer of Electric Charge

• Objects can be charged by:1. Friction2. Contact3. Inductiono As a charge object approaches an

uncharged object, it will push like charges away and attract opposite charges.

Electric Force

• The force that attracts or repels electric charges is electric force.

• Electric force depends on charge and distance– The greater the difference in charges, the

stronger the force.– The greater the distance between charges

the weaker the force.

Electric Force

• Electric force acts through a field– Electric field – the space around an electric

charge that is affected by it.–Often shown by drawing electric field lines

that point in the direction a positive charge would move.– Electric field lines never cross one another.

Electric Force