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H. PHYSICS
CHAPTER 16: ELECTRIC CHARGE AND ELECTRIC FIELD
I.
16
OVERVIEW
Starting in 1740 Benjamin Franklin studied the electricity produced by friction, such as shoes rubbed on
a carpet. He proposed that rubbing transferred an "electric fluid" from one body to the other. In 1752,
he performed his famous kite in a storm experiment where he was able to draw "electrical fire" from a
cloud.
II.
OBJECTIVES
Upon completion of this unit, the student should be able to explain
the following:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
III.
Static electricity
Conservation of electric charge
Electric charge in an atom
Insulators and conductors
Induced charge
The electroscope
Coulomb's law
Permittivity of free space
Coulomb's law and vectors (solving problems)
The electric field
Field lines
Electric fields and conductors
ASSIGNMENTS (CHAPTER 16)
SECTION 1: Read pages 476-485
Solve Problems 1-8, 11, 13, 41, 42
DUE DATE: ________________
SECTION 2: Read pages 486-492
Solve Problems 21-27, 37, 43, 45, 49, 53
DUE DATE: ________________
IV.
QUIZZES
SECTION 1:
DATE: ________________
SECTION 2:
DATE: ________________
WORKSHEET: COULOMB’ S LAW AND ELECTRIC FIELD
1.
One coulomb is an enormous charge. To get some idea of its size, assume that you are holding a basketball
with a charge of 1.0 C. Your friend is 1.0 km away and holding another ball with an opposite charge of 1.0
C. What is the force you must apply to the ball to keep it from zipping out of your hand and accelerating
towards your friend?
9.0kN
2.
In a coulomb force experiment, a student determines that the force between two equally charged spheres is
300. nN when the centers are separated by 20. mm. What is the
a.
b.
charge on each sphere?
number of excess electrons on each sphere?
a. 1.15x10-10C
b. 7.21x108 e
3.
A comb is held 5.0 cm from a small balloon. The charge on the comb is twice the charge on the balloon.
a.
b.
If the force of repulsion is 60. mN, find the charge on the balloon.
By how many electrons is the charge on the balloon unbalanced?
a. 9.1x10-8C
b. 5.7x1011 e
4.
A small conducting sphere has a charge of 80. nC. It is touched by another similar sized conducting sphere
(neutral), which is subsequently moved to a position 60. mm from the first sphere.
a.
b.
What will be the magnitude of the force between them? Will is be attractive or repulsive?
How many excess electrons were originally on the sphere?
a.4.0 x l0-3 N
b.5.0 x 1011 e
5.
A +200. nC test sphere is 40. mm to the right of another charged sphere. There is an attractive force of 500.
nN.
a.
b.
c.
What is the electric field strength?
What is the electric field direction?
What is the magnitude of the charge of the source?
a. 2.5 N/C
b. to the left
c. 4.4x10-13 C
6.
A particle of mass 0.010 g and charge 30. nC is placed in a field of strength 15 kN/C directed to the left.
Determine the size and direction of the acceleration of the particle.
45 m/s2 to the left
[0.756 i - 4.36 j]
[0.366 d]
[5.25 µC]