Static Electricity
Physics
Ms. Henry
School House Rock: Title 49 (Chapter 1)
Electrons
Thank you Ben…
Franklin came up with the convention of calling the 2
types of charges, positive & negative.
Getting Charged…
Group Name
Paper Pick Up
Michael
H.
Tyler I.
Bri M.
Gelatin Stalagmites
Mitchell
R.
Matt S.
Haydon C.
Runaway Soda Can
Alex L.
Bobby A.
Eric H.
Swinging “Pith” of Death
Austin K.
Wade M.
Elaine S.
Dancing Bunnies
Sarah C.
Becca C.
Jessica R.
Swirling Vortex of Terror
Zak N.
Scott M.
Cameron
C
The Electroscope
Jake W.
Tyler F.
Julee L.
Kaitlyn W.
Within your groups.
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Pick one person to find your bin with your
materials.
Complete the instructions with your group.
Fill out the front side of the worksheet as you
work.
Prepare for a very brief presentation to the
class of your activity.
Present.
As other groups are presenting, you should be
completing the back side of your worksheet.
From our labs…
•Two
kinds of charges were not created alone, but in
pairs.
•Matter normally contains both charges, positive and
negative.
•Contact separates them.
•Charge is conserved; or individual charges are never
created nor destroyed. Positive and negative charges
are separated through the transfer of electrons.
Coulomb’s Law
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Electric Force depends on:
◦ Distance (r)
◦ Charge (q)
K=9.0x109 N∙m2/C2
(when charges are measured in coulombs, distance in
meters and force in Newtons.)
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Vector Quantity: needs a magnitude & direction
•1 Coulomb = 6.24x1018 electrons or protons
•Elementary charge: 1.60x10-19C
(aka: Charge of a proton or electron)
Electric Force Problems
What are you given?
 What do you need to figure out?
 What are you going to use to figure it out?
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p. 550: Specific Problem Solving guidelines.
Example
A negative charge of -2.0x10-4C and a positive charge of
8.0x10-4C are separated by 0.30m.
What is the force between the two charges?
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When does Coulomb’s Law apply?
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In general, where the size of the charge is
small compared to the distance between
them.
The object is a sphere.
When does Coulomb’s Law not apply?
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When the distribution of charge is farther
from the test point than the size of the
distribution itself.
Homework
p. 558 #26, 27, 33, 34, 36
 p. 559 #52, 57
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