The document provides an introduction to forces and their interactions, defining force as a push or pull that causes motion changes in objects. It categorizes forces into non-contact and contact forces, detailing examples such as normal force, friction force, and gravitational force, and discusses applications of force. Additionally, it explains net force calculations and includes various scenarios to illustrate the types of forces in action.

1. Lesson 1:
FORCES AND
INTERACTION

2. INTRO.:  What is a FORCE?
is a push or a pull
.
- an interaction between
two or more bodies that
when unopposed causes
a change in the state of
motion of the objects.
Application of Force
Setting an object
into motion
Bringing it to STOP
Change the shape of
an object

3. ISAAC NEWTON
NEWTON (N) – unit of force
FORCE is a Vector Quantity
Magnitude + Direction

4. CLASSIFICATION OF FORCE
Non-contact force
Contact force
is a force exerted by direct
physical contact
between two objects
is a force applied to an object by
another body that is not in direct
contact with it.
1. Normal Force (FN)
2. Applied Force (FA)
3. Friction Force (FF)
4. Tension Force (FT)
5. Spring/Restoring Force (FS)
6. Air Resistance (FAir)
7. Bouyant Force (FB)
1. Gravitational Force (FG)
2. Electromagnetic (FE or FM)

5. APPLICATION OF FORCE
A - Setting an object into motion B - Bringing it to STOP C- Change
the shape of an object
1. Stretching a Rubber
Band
2. Falling apple
3. Compressing a
spring
4. Rocket launch
5. Tug of war
6. Squeezing a tin can
7. A ball on top of the
table
8. Arranging the chair
9. Opening the door

6. APPLICATION OF FORCE
A - Setting an object into motion B - Bringing it to STOP C- Change
the shape of an object
1. Stretching a Rubber
Band
2. Falling apple
3. Compressing a
spring
4. Rocket launch
5. Tug of war
6. Squeezing a tin can
7. A ball on top of the
table
8. Arranging the chair
9. Opening the door
C
A
C
A
A
C
B
A
A
B

7. 1cm = 10 N
1. 40 N, SE
2. 70 N, NE
3. 50 N, NW
4. 35 N, SW
5. 90 N, S

8. 1cm = 10 N
1. 40 N, SE
2. 70 N, NE
3. 50 N, NW
4. 35 N, SW
5. 90 N, S
(40 N,SE)
(70 N,NE)
(50 N,NW)
(35 N,SW)
(90 N,S)

9. Types of Forces
Determine the forces involved in the various situation.
1. A book resting on top of the table _________,_________
2. A child slides down a playground slide. _________, __________,
________
3. A skydiver is falling at terminal velocity. _________ ,_________
4. A balloon filled with helium is floating upwards. _________ ,_________
5. Pulling a bucket of water from the well _________,
__________, ________
6. A compass needle points north. __________
7. The moon causes the ocean tides on Earth. __________
8. A balloon sticks to a wall after being rubbed against hair. __________
9. Motorcycle shock moves over bumps or rough terrain. __________
10.A boat floating in the water ___________
11.Swinging a pendulum
_________,__________,_________

10. Types of Forces
Determine the forces involved in the various situation.
1. A book resting on top of the table _________,_________
2. A child slides down a playground slide. _________, __________,
________
3. A skydiver is falling at terminal velocity. _________ ,_________
4. A balloon filled with helium is floating upwards. _________ ,_________
5. Pulling a bucket of water from the well _________,
__________, ________
6. A compass needle points north. __________
7. The moon causes the ocean tides on Earth. __________
8. A balloon sticks to a wall after being rubbed against hair. __________
9. Motorcycle shock moves over bumps or rough terrain. __________
10.A boat floating in the water ___________
11.Swinging a pendulum
_________,__________,_________
Normal
Force
Gravitational
Force
Normal
Force
Gravitational
Force
Friction Force
Air Resistance Gravitational
Force
Buoyant Force Gravitational
Force
Tension Force Friction Force Applied Force
Electromagnetic Force
Gravitational Force
Electromagnetic Force
Spring/Restoring Force
Buoyant Force
Tension Force Applied Force Gravitational Force

11. Net Force (Fnet)
- is the sum of all the forces
acting on an object.
Formula for Net Force
Fnet​
= F1 + F2
Where:
Fnet​= Net force acting on
object
F1 = 1ST
force applied
F2 = 2nd
force applied
Problem: Two people pushes
a crate at the same time in the
same direction, each of them
exert a force of 2N. How much
is the total net force?
Solution:
Fnet​
= F1 + F2
Fnet​
= 2N +
2N
Fnet​
= 4N
Problem: Two people pushes a
crate at the same time exerting
each of them a force of 2N but
in opposite direction. How
much is the total net force?
Solution:
Fnet​
= F1 + F2
Fnet​
= 2N + (-
2N)
Fnet​
= 0N
Problem: Two people pushes a
crate at the same time but in
opposite direction with
different amount of force
exerted. One exert a force of
4N and the other exert 2N. How
much is the total net force?
Solution:
Fnet​
= F1 + F2
Fnet​
= 4N + (-
2N)
Fnet​
= 2N

12. Normal Force (FN)
- a force exerted by a
surface in contact with an
object.
Formula for Normal Force
FN​
=FG​
= m g
⋅
Where:
FN​= Normal force
FG = Gravitational force (weight)
m = Mass of the object
g = Acceleration due to gravity (9.8 m/s2
)
Problem: A box with a mass of
10 kg rests on a flat table.
What is the normal force
acting on the box?
Solution:
FN ​
= FG​
= m g
⋅
FN ​
= FG​
= 10 kg x 9.8 m/s2
FN ​
= FG​
= 98 kg . m/s2
FN ​
= FG​
= 98 N
1 kg . m/s2
= 1
N
Problem: A 10kg box is on a flat
table, and a 20N downward force
is applied. What is the normal
force?
Solution:
FN ​
= FG​
= (m g) + F
⋅ A
FN ​
= FG​
= (10 kg x 9.8 m/s2
) + 20N
FN ​
= FG​
= 98 kg . m/s2
+ 20N
FN ​
= FG​
= 98 N + 20N
FN ​
= FG​
= 118 N