3. Title
FORCE
CONTACT AND NON-CONTACT FORCE
INTERNAL AND EXTERNAL FORCE
BALANCED AND UNBALANCED FORCE
4. FORCE
A force is an influence which tends to set a stationary body
In motion or which tends to change the speed and
direction of a moving body or which tends to change the
shape of a body.
Unit of force is newton(N).
5. CONTACT FORCE
A force that can be applied only when it is in contact with
an object is called a contact force.
Eg: muscular force
6. NON-CONTACT FORCE
A force that can be applied without any contact between
two bodies is called non-contact force.
Eg: Magnetic force
7. INTERNAL FORCE
A force exerted by internally is called internal
force.
8. EXTERNAL FORCE
A force exerted by externally is called external
force.
9. BALANCED FORCE
When a number of forces act on a body, and the
resultant of these forces is zero, then the forces
are said to be balanced.
10. UNBALANCED FORCE
When a number of forces act on a body, the
resultant of forces is not zero, the forces are said
to be unbalanced.