CHARADES
Let’s Play
FORCES
Lesson 1
MOST ESSENTIAL
LEARNING COMPETENCY
Investigate the
relationship between the
amount of force applied
and the mass of the object
to the amount of change
in the object’s motion.
S8FE-Ia-15
LET’S DEFINE
Force is generally defined as
the push and pull applied to
“FORCE” an object.
It is also defined as an
influence that changes the
motion of an object.
It is expressed in Newton (N).
PUSH PULL
A push is a force that moves A pull is a force that moves
something away from you or from something towards you or from the
the direction of the force. opposite direction of the force.
Activity 1
“EFFECT OF
FORCE ON A
BALL”
Examine the ball on top of the table in
the figure.
Activity 1
“EFFECT OF FORCE ON A BALL”
To accurately describe the forces acting on an object, let us
examine the figure below:
MAGNITUDE DIRECTION
POINT OF APPLICATION LINE OF ACTION
MAGNITUDE
- refers to how strong the force is.
- usually expressed in Newton (N), named after
the famous physicist Sir Isaac Newton.
DIRECTION
- refers to the point to where the object goes.
- refers to the location where the force is
applied.
MAGNITUDE
POINT OF APPLICATION
- refers to the straight line passing through
the point of application, and is parallel to the
DIRECTION
direction of the force.
LINE OF ACTION
2 TYPES OF
FORCE 1. Contact Forces
2. Non-contact Force
CONTACT
FORCES
These are forces wherein an
object needs physical contact
to another object.
Contact forces directly affect
objects by making them move,
change shape, or stop moving.
APPLIED FRICTION NORMAL TENSION
Example
- refers to the force exerted by a person or
F
an object towards another person or object.
APPLIED
- depending on who or
what applies the force, we
write it smaller next to the
Symbol letter F.
of
F F F
Force
BOY GIRL BALL
F
APPLIED
GIRL
F
APPLIED
BALL
F
APPLIED
BOY
- refers to the force that acts opposite or
FF
against another object.
FRICTION
- a force that happens
when two surfaces rub
against each other.
Symbol
of - this causes the movement
Friction
Force of an object to slow
down.
FRICTION
FRICTION
FRICTION
- is the force that acts perpendicular to
FN
the surface of the object in contact with.
NORMAL
Symbol
of
Normal
Force
- is the force applied to string, rope, chain
T
or cable. Its symbol is T.
TENSION
- is a pulling force
transmitted through a wire,
Example rope, or string when an
Symbol object is connected to it.
of
Tension
Force
TENSION
Example
TENSION
Example
LET’S DO IT
Identify the following illustrations according to the type of contact
force: applied force, friction force, normal force, or tension force.
LET’S DO IT
Identify the following illustrations according to the type of contact
force: applied force, friction force, normal force, or tension force.
LET’S DO IT
Identify the following illustrations according to the type of contact
force: applied force, friction force, normal force, or tension force.
LET’S DO IT
Identify the following illustrations according to the type of contact
force: applied force, friction force, normal force, or tension force.
NON-CONTACT
FORCES
Forces where objects do
not touch or contact
with each other. These
forces act over a zone
or area called field.
MAGNETIC GRAVITY
Magnetic force is a type of Gravity is a force that pulls
non-contact force that acts objects towards each other.
between magnets or magnetic It is what keeps us on the
objects. ground and what makes things
fall down.
Example Example
MAGNETIC are forces exerted on a
field of attraction or
repulsion as in the
case of magnets and other
magnetic materials.
MAGNETIC
MAGNETIC
Gravity is a force that pulls GRAVITY
objects towards each other.
It is what keeps us on the
ground and what makes things
fall down.
GRAVITY
BALANCED FORCES
Forces that are equal in magnitude but opposite
in direction are called balanced forces.
BALANCED FORCES
Balanced forces do not cause a change in motion.
When balanced forces act on an object at rest, the
object will not move.
UNBALANCED FORCES
Forces that cause a change in the motion of
an object are unbalanced forces.
UNBALANCED FORCES
Unbalanced forces are not equal and in opposite
direction.
NET OR
RESULTANT FORCE
Net force or resultant force
is the sum of all forces
acting on an object.
Two or more forces in the same
line of action exerted on an
object are balanced if their
effects cancel each other.
NET OR
RESULTANT FORCE
F NET
Symbol
of Net
Force
NET OR
RESULTANT FORCE
Formula for Net Force:
NET OR
RESULTANT FORCE
NET OR
RESULTANT FORCE
NET OR RESULTANT FORCE
NET OR RESULTANT FORCE
Activity 2
Questions:
“FORCES ON
OBJECTS AT 1. Is the block of wood at
REST” rest or in motion?
_______________
2. Refer to the figure. Draw
the forces acting on the
block of wood. Use
the red dot as the origin of
the forces.
Activity 3
“BALANCE OF FORCES”
Activity 3
“BALANCE OF FORCES”
Activity 4
“UNBALANCED FORCES”
Activity 4
“UNBALANCED FORCES”
SHORT QUIZ
Let’s have a
WHAT I HAVE LEARNED
Fill in the blanks with correct word/s. Write your answers on a separate
sheet of paper.
1. Any push or pull is called ________________.
2. ________________ refers to the size or strength of the force while
________________ points to where the object goes. The direction of the
arrowhead indicates the direction of the force. The length of the arrow
represents the amount of force (relative magnitude).
3. There are two types of forces, namely ________________ and
________________.
4. Applied, friction, normal and tensional forces are examples of
________________ forces.
5. Gravitational and magnetic forces are examples of ________________ forces.
WHAT I HAVE LEARNED
6. ________________ are forces that are equal in magnitude but
opposite in direction.
7. ________________ are forces that cause a change in the motion of
an object.
8. The sum of all forces acting in an object is called ______________.
9. If the forces in an object are balanced, the net force is
________________.
10. If the forces in an object are unbalanced, the net force is
________________.
