Page 10 - GALIET PHYSICS BLOSSOMS III

Fig. 33
What Happens When We Bring Other Test Charges Electrons = -à(always carry a negative charge)
Protons = +à(always carry a positive charge)
According to Coulomb’s Law, electric charges, attractive or repellent, exert forces on each other (just as a massive object exerts a gravitational force on every other massive body; however, unlike an electric force, gravitational forces are always attractive!):
• If we bring a positively charged object close to the positively charged metal ball, then the charges will repel each other.
• If we bring a negatively charged object close to the positively charged metal ball, then the charges will attract each other.
These are just some observations from class notes:
• Extending outwards in all directions from any charged particle is an electric field, which determines how a particle influences other charged particles.
• The electric field decreases in strength with distance; however, all other near or far-off charged particles can feel its presence.
• If a charged particle, whether by heating or collision, vibrates, it changes its position, which causes its electric field to change. This changing field also changes the electrical force exerted on other charges. This disturbance travels as a wave interacting with distant charged particles.
• An electric charge creates an electric field, which acts back on electric charge.
• An electric current creates a magnetic field, which acts back on electric current.
3 http://www.tutorvista.com/content/physics/physics-i/static-electric-current/charging-conduction-induction.php. November 7, 2012.
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