Quarter 2- Lesson 2
At the end of this lesson, learners should
be able to:
1. compare translational motion with
rotational motion; and
2. define mechanical equilibrium.
Rigid bodies are
objects where in all the
parts remain at constant
or fixed distances from
every other parts as the
object rotates.
Translational Motion- refers to
linear motion wherein every
particles has the same
instantaneous velocity.
Rotational Motion- refers to
motion of a body about a fixed
axis of rotation wherein the
particles have the same
instantaneous angular velocity.
Angular velocity, time
rate at which an
object rotates, or
revolves, about an
axis, or at which the
angular
displacement
between two bodies
changes
V=(w)(r)
(𝑑𝑒𝑔𝑟𝑒𝑒)(π)
𝑟𝑎𝑑 =
180
1
𝑇=
𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦
𝑐𝑦𝑐𝑙𝑒𝑠
𝑓=
𝑡𝑖𝑚𝑒
Equilibrium is
achieved when
the sum of the
forces acting on
the body is
zero.
Static
Equilibriumthe body is at
rest.
Dynamic
Equilibriumthe body is in the
motion at a
constant velocity.
The Center of
gravity (cg) of an
object is located at
the point from where
it can be suspended
without tending to
rotate.
It is a point from where
all at the weight of an
object may be
concentrated.
It usually coincides
with the center of mass
which is the average
position of all particles
of the object.
The center of gravity of
objects varies because
of their varying shapes
and sizes.
Regular Objects- cg is
in the geometric
center.
Irregular object- cg is
in more mass area.
The center of gravity of
some objects may be a
point where no mass
exist like a ring.
Using Plumb line and Plumb bob.
Stable Equilibrium
Unstable Equilibrium
Neutral Equilibrium
Any small
displacement from an
equilibrium position
results in a force that
tends to return the
objects to their
original position.
When a disturbing
force is applied, the
center of gravity is
lowered and moves
away from its original
position.
When the center of
gravity of a body lies
at the point of
suspension or support
the body is to be in
neutral equilibrium.