This document discusses the concept of force. It defines force as an influence that can cause an object at rest to be set in motion, change the speed or direction of a moving object, or change the speed of a body. It describes balanced and unbalanced forces. Balanced forces have a net force of zero, while unbalanced forces have a non-zero net force. The document also discusses Newton's First Law of Motion, which states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. It further explains the concept of inertia and how inertia is related to an object's mass.

1. Submitted by
SREEKALA L
Reg:no:13982022
Physical science
K.U.C.T.E Kulakkada

2. FORCE

3. FORCE
• A force is an influence which tends to set a
stationary
• object in motion or which tends to change the speed
• and direction of a moving body or which tends to
• change the speed of body.

4. Images of force

5. Balanced force
• When a number of force acts on a body and the resultant of these
forces is zero , then the force is said to be balanced.

6. Unbalanced force
• When a number of forces acts on a body , the resultant of force is not
zero , the force is said to be unbalanced.

7. Balanced force

8. Unbalanced force

9. Characteristics of force
• Force is required to move an object from a
state of rest.
• Force is required to increase or decrease the
speed of a moving object.
• Force is required to change the direction of
an object moving in a particular direction.
• To stop an object moving in a particular
direction of force is to be applied in the
opposite direction.

10. NEWTON’S FIRST LAW OF
MOTION
• Any body continues to be in a state of rest or of
uniform motion in a straight line until an unbalanced
external force is applied on it.

11. Inertia
AN OBJECY CANNOT BY ITSELF
CHANGE ITS STATE OR REST OR ITS
UNIFORM MOTION IN A STRAIGHT LINE.
THIS IS INERTIA

12. Inertia

13. Inertia of rest
AN OBJECT IN A STATE OF REST
HAS THE TENDENCY TO CONTINUE
IN THAT STATE
Inertia of motion
AN OBJECT IN A STATE OF MOTION
HAS THE TENDENCY TO CONTINUE
IN THAT STATE

14. Mass and Inertia
• Mass is the measure of inertia of a body. The
inertia of two objects is not the same . If
they have same speed or the same momentum
. Mass or inertia is an intrinsic property of an
object.