1. FORCES AND MOTION
MODULE 1

2. Let’s look back…
In Grade 7, you described an object’s motion in terms of displacement, speed or velocity, and acceleration.
Then you were also introduced to non-uniform motion where the object covers unequal distances or displacements at equal intervals of time.

3. Most of the motions we come across in our daily life are non-uniform and the primary cause of changes in motion is FORCE.
In this module, you will learn about the effects of force on motion. Newton’s Three Laws of Motion – the central organizing principle of classical mechanics – will be presented and applied to real-life situations.

4. Important Words to Remember
Force
Motion
is just a fancy word for pushing or pulling. 
is the changing of position with respect to a frame of reference

5. Do forces always result in motion?
At the end of Module 1, you will be able to answer the following key questions:
Do forces always result in motion?
What are the conditions for an object to stay at rest, to keep moving at constant velocity, or to move with increasing velocity?
How is force related to acceleration?

6. What makes objects move?
Group Activity
What makes objects move?
Why do objects move in different ways? Why are some objects faster than the others?
What makes objects stay in place?

7. Answer this…
Will this object move by itself?
How can we make this object move?
While it is moving, how can we make the object speed up or slow down?
How can you make it stop?
How can we make it change its direction?

8. Answers No. Will this object move by itself?
How can we make this object move?
While it is moving, how can we make the object speed up or slow down?
How can make it stop?
How can we make it change its direction?
No.
By applying force/ by pushing or pulling it
By applying more force
By applying resistant force
By applying force
By applying force at different direction

9. Force and Motion Let’s watch this!

10. LET’S ANALYZE No. No. Will this object move by itself?
How can we make an object move?
While it is moving, how can we make the object speed up or slow down?
How can make it stop?
How can we make it change its direction?
No.
Force can make the object move
Force can speed up and slow down motion
Force can make an object stop
Force can change the direction of motion
No.
By applying force/ by pushing or pulling it
By applying more force
By applying resistant force
By applying force
By applying force at different direction

11. HOW DO FORCES AFFECT MOTION?
Force can cause an object to move
Force can cause an object to stop
Force can cause acceleration (speed up)
Force can cause deceleration (slow down)
Force can change direction of motion

12. Noncontact Force – force that acts at a distance.
TWO TYPES OF FORCES
Contact Force – force that acts on objects that are touching each other.
Noncontact Force – force that acts at a distance.

13. Types of Contact Forces
normal force: the force of an object which supports another object such as a book laying on a table
applied force: a force applied to something
frictional force: the force that opposes motion
tension force: the force of tension in a wire, rope or cable
spring force: force created by a spring