Warmup & Review
A 10 mg housefly has developed a charge of -100 pC. On a normal day, with a 100 N/C
electric field directed downward,
F = qE
What is the direction of the force on the fly? Does the fly “feel heavy” or “feel
light” – that is, is it easier or harder for the fly to stay airborne?
It feels light
What approximate fraction of the fly’s weight does this force represent?
F = (100 x 10 -12C) (100 N/C)
F = 1.0 x 10 N8
Electric fields and conductors
The electric field inside the conductor is zero.
All excess cha