EQUILIBRIUM:
“TO BE (BALANCED) OR NOT TO BE
(BALANCED)? – THAT IS THE
QUESTION.”
What Is Equilibrium?
EQUILIBRIUM
BALANCE
What Is Equilibrium?
• A body is said to be in equilibrium if it is
in a self-sustaining state indefinitely.
What Is Equilibrium?
• A body is said to be in equilibrium if it is
in a self-sustaining state indefinitely.
self-sustainability
no outside help
What do we mean by OUTSIDE HELP?
• In Physics, “outside help” is anything that
would cause the object to change its state of
equilibrium.
What do we mean by OUTSIDE HELP?
• In Physics, “outside help” is anything that
would cause the object to change its state of
equilibrium.
“OUTSIDE HELP”
PHYSICS AGENT(S)
What do we mean by OUTSIDE HELP?
• In Physics, “outside help” is anything that
would cause the object to change its state of
equilibrium.
“OUTSIDE HELP”
PHYSICS AGENT(S)
• The object is out of equilibrium while acted
upon by an agent.
The Simplest State
• Object NOT in motion.
The Simplest State
• Object NOT in motion.
• 3 types
The Simplest State
Identifier(s)
• Object NOT in motion.
• 3 types
Physics Concept(s)
• STATIC EQUILIBRIUM
The Simplest State
Identifier(s)
• Object NOT in motion.
Motion Type: @ REST
• 3 types
Physics Concept(s)
• STATIC EQUILIBRIUM
@ REST
The Simplest State
Identifier(s)
• Object NOT in motion.
Motion Type: @ REST
Physics Concept(s)
• STATIC EQUILIBRIUM
@ REST
• 3 types
• Stable
• Unstable
• Indifferent
The Simplest State
Identifier(s)
• Object NOT in motion.
Motion Type: @ REST
Physics Concept(s)
• STATIC EQUILIBRIUM
@ REST
• 3 types
• Stable
• Unstable
• Indifferent is also called
neutral
What Is the Difference?
Identifier(s)
• Object NOT in motion.
Motion Type: @ REST
Physics Concept(s)
• STATIC EQUILIBRIUM
@ REST
• 3 types
• Stable
• Unstable
• Indifferent
Describing each state
• Physics uses the concept of a “center-of-mass”
to describe and track an object’s motion (or
lack thereof) over time.
Describing each state
• Physics uses the concept of a “center-of-mass”
to describe and track an object’s motion (or
lack thereof) over time.
• The center of mass of an object is the single
point where all its mass is symbolically
located.
Describing each state
• Physics uses the concept of “center-of-mass”
to describe and track an object’s motion (or
lack thereof) over time.
• The center of mass of an object is the single
point where all its mass is symbolically
located.
C.O.M.
Shape, density distribution, size
C.O.M. of some geometric figures
• CONE
.
• SPHERE
.
• SOLID RING
.
C.O.M. of some geometric figures
• CONE
.
• SPHERE
.
OUTSIDE OBJECT
• SOLID RING
.
What Is the Difference?
Identifier(s)
• Object NOT in motion.
Motion Type: @ REST
• 3 types
Physics Concept(s)
• STATIC EQUILIBRIUM
@ REST
C.O.M. location
• Stable
. low
.
• Unstable
high
• Indifferent
.
same
• Given a “choice”, objects seek states of lower
c.o.m. (center of mass).
• Given a “choice”, objects seek states of lower
c.o.m. (center of mass).
• Any object in unstable equilibrium, when
disturbed, seeks a stable equilibrium (it may
or may not achieve it).
• Given a “choice”, objects seek states of lower
c.o.m. (center of mass).
• Any object in unstable equilibrium, when
disturbed, seeks a stable equilibrium (it may
or may not achieve it).
• Any object in stable equilibrium, when
disturbed, seeks to go back to its original state
(of stable equilibrium).
INERTIA
• Ability for an object to sustain its state of
equilibrium indefinitely.
INERTIA
• Ability for an object to sustain its state of
equilibrium indefinitely.
• For objects at rest, the measure of the object’s
inertia is the object’s mass.
INERTIA
• Ability for an object to sustain its state of
equilibrium indefinitely.
• For objects at rest, the measure of the object’s
inertia is the object’s mass.
PHYSICS CONCEPT
(@ REST) INERTIA
MEASURE
MASS
THE END
© Lilian Wehner