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Newton’s
laws of
Motion
Work,
Energy
and Power
Fluids
Direct
Current
(DC)
Nerve
Conduction
Instructor: Sujood Alazzam
2016/2017
Wave
properties
of light
Ionizing
Radiation
CHAPTER OUTLINE
Newton’s laws of Motion:
3.1 Force, Weight, and Gravitational Mass.
3.3 Newton’s first law.
3.4 Equilibrium
3.5 Newton’s third law
3.6 Newton’s second law
3.10 Weight.
3.12 friction.
9.2 The weight on a spring.
9.3 The physical pendulum.
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Lecture 1:
What is a force?
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3.1 Force
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What is a force?
A force is an influence on a system or object which,
acting alone, will cause the motion of the system or object
to change. If a system or object at rest is subjected to a
non-zero force it will start to move.
We know that a force can be a push or a pull
acting on an object.
Force

…the agency of change.

…changes the velocity.

…is a vector quantity.

...measured in Newton’s.
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Cont.
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
There is a good chance that 2 forces can be acting on an object
at any one time.

Examples:
Lifting
something
Dragging
something
3.3 Newton’s First Law
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
Law of Inertia

Newton’s 1st Law: “Every
object continues in a state of rest,
or of uniform motion in a straight
line, unless it is compelled to
change that state by forces
acting upon it”.
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An equivalent statement of the first law is
that if there is no force on an object, or if
there is no net force when two or more
forces act on the object, then:
 an object at rest remains at rest, and
 an object in motion continues to move
with constant velocity.
3.4 EQUILIBRIUM
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Newton's first law tells us that the state of 10
motion of an object remains unchanged
whenever the net force on the object is zero.
This can happen if no forces act on an object.
More commonly, it occurs because two or
more forces acting on an object add to zero or
"balance." When the state of motion of an
object remains unchanged even though two or
more forces act upon it, the object is said to
be in equilibrium
What is Net Force?
F1
F2
F3
Fnet
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When more than one
force acts on a body,
the net force (resultant
force) is the vector
combination of all the
forces, i.e., the “net
effect.”
3.5 Newton’s Second Law
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The Sum of the Forces acting
on a body is proportional to
the acceleration that the body
experiences
F  a
 F = (mass) a


F  ma
Net Force
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F
x
 ma x
 Fy  ma y
 Fz  ma z
3.6 Newton’s Third Law
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
Action-Reaction

For every action force there is
an equal and opposite reaction
force
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