The
word electric is comes from the Greek word ember,
meaning ‘electron’.
Electrostatics
is about electric charges at rest.
The static of electric charges are produced
by friction between dissimilar objects.
1.1 Electric Charge
 |
|||
There are two types of charge; positive charge (+) and negative charge (-).
Friction removes
some electrons from one object to other. The one acquiring e- is said to negative while the one that lost electrons is said to be positive.
Interaction between charges.
A positively
charged rod is repelled by another positively charged rod while other
positively charged rod is attract to another negatively charged rod
“When a certain amount of charge is produced
on one body (by rubbing), then an equal amount of the opposite type of charge
is produced on another body” - Franklin
Basis of electric charge
Electricity starts
inside the atom itself. Electric charge is one of the fundamental attributes of
the particles of which matter is made.
The structure of
matter made up of three particles:
·
Negatively charges (electron)
·
Positively charges (proton)
·
Uncharged neutron (neutron)
Figure:
Properties of particles in an atom
Proton and neutron
is located in the nucleus while
electron arranged in shells around the nucleus
The positive ion
is when one or more electrons are losing
from an atom. The negative ion is when one or more electrons are gained
in an atom. This gaining and losing electrons called ionization.
Example:
In a storm,
lightning is the visible electric discharge that occurs between charged rain
clouds and the Earth.
1.1 COULOMB’S
LAW
Charles Augustin de
Coulomb (1736-1806) studied that electric forces using torsion balance in 1780s.
Torsion balance was able to produce charged spheres. Coulomb found that the
electric force is proportional to 
. Thus, when the
distance, r is doubles, the forces decreases to 1/4 of its initial values.
. Thus, when the
distance, r is doubles, the forces decreases to 1/4 of its initial values.
Quantity of charge, q divided into two points of electric charges,
and 
. The forces exert on
each other are proportional to each charge and also proportional to the product
of the two charges.
and 
. The forces exert on
each other are proportional to each charge and also proportional to the product
of the two charges.
F is the magnitude of
the force while the two point charges apart by distance, r where k is proportional constant.
The magnitude, F is:
- · Directly proportional to the product of two charges
- ·
Inversely proportional to the square of
the distance between charges,
When 
and 
have the same sign either positive or
negative, the forces are repulsive. But when the charges have opposite signs,
the forces are attractive.
and 
have the same sign either positive or
negative, the forces are repulsive. But when the charges have opposite signs,
the forces are attractive.
SI
unit of electric charge, 1C
In SI units, the
constant, k usually writes as
. Thus,
the force rewrite as
. Thus,
the force rewrite as
Where 
and 
and 
REFERENCES
- Ahmad, M. & Zakaria, Z. (2014). Physics 3 DAS24603. 1st ed. UTHM: Centre of Diploma Studies.
- N. Math, S. Initiative (1807). Electrostatics: Electric Charge & Electric Field. Retrieved from http://www.marion.kyschools.us/userfiles/87/Classes/854/Handout%2001%20-%20NOTES%20-%20Electrostatics.pdf
No comments:
Post a Comment