This document introduces forces and motion. It reviews concepts from grade 7 like displacement, speed, velocity, and acceleration. It states that most motions involve non-uniform changes caused by forces. The document previews Newton's Three Laws of Motion and how they will be applied. Key questions are presented about the relationship between forces and motion, rest, and changes in velocity. Students are asked to consider what causes motion and differences in speed. They are given examples to think through involving applying or resisting forces to make objects move, change speed, stop, or alter direction.

3. ACTIVITY 1

5. FORCES AND MOTION
MODULE 1

6. 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.

7. • 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.

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

9. 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?

10. 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?

11. Answer this…
a) Will this object move by itself?
b) How can we make this object
move?
c) While it is moving, how can we
make the object speed up or slow
down?
d) How can you make it stop?
e) How can we make it change its
direction?

12. Answers
a) Will this object move by itself?
b) How can we make this object
move?
c) While it is moving, how can we
make the object speed up or
slow down?
d) How can make it stop?
e) 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

13. Let’s watch this!
• Force and Motion
https://www.youtube.com/watch?v=LEs9J2IQIZY

14. 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

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

16. 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