Forces can be pushes, pulls, or a combination of both. There are two main types of forces - contact forces, which occur when objects touch, and non-contact forces, which occur over a distance. Contact forces include frictional forces from objects sliding against each other and muscular forces from human and animal muscles. Non-contact forces include gravitational forces, magnetic forces, and electrostatic forces. A force is any interaction that, when unopposed, will change the motion of an object.

1. FORCE
AND
pRESSURE

2. - playing a guitar - scrubbing the floor
- sawing wood - rowing a boat
• A pull is when we apply a force to
move an object towards our body
• A force to move an object away from
our bodies
FORCE
A force is a push or a pull or both. A force cannot be seen but we can feel and
observe the effects of the force.
PUSH PULL
COMBINATION OF PUSH AND PULL

3. Force
Contact
Muscular Frictional
Non
Contact
Gravitational Magnetic Electrostatic

4. Contact forces are those types of forces which result
when the two interacting
objects are perceived to be physically contacting each
other. Examples of contact forces include
 Frictional forces
 Muscular forces

5. Frictional Force
The friction force is the force exerted by a surface as an
object moves across it or makes an effort to move
across it. There are at least two types of friction force -
sliding and static friction. For example, if a book slides
across the surface of a desk, then the desk exerts a
friction force in the opposite direction of its motion.
Rowing a boat

6. The muscular force comes from muscles of man or
animals. Every physical activity comes with a use a
muscle , Hence they are muscular forces.
RUNNING

7. Scrubbing the
floor
Sawing wood

8. Non Contact forces are those types
of forces which result even when
the two interacting objects are not
in physical contact with each other,
yet are able to exert a push or pull
despite their physical separation.
Examples of Non Contact forces
include gravitational forces.

9. Gravitational Force
The force of gravity is the force with which the earth,
moon, or other massively large object attracts
another object towards itself. By definition, this is the
weight of the object. All objects upon earth
experience a force of gravity which is directed
"downward" towards the center of the earth.

11. Magnetic Force
Attraction or repulsion that arises between electrically
charged particles because of their motion; the basic
force responsible for the action of electric motors and the
attraction of magnets for iron. Electric forces exist among
stationary electric charges; both electric and magnetic
forces exist among moving electric charges.

12. Bar Magnet…

13. Electrostatic Force
The force exerted by stationary objects bearing
electric charge on other stationary objects bearing
electric charge. If the charges are of the same sign,
then the force is repulsive; if they are of opposite
signs, the force is attractive. The strength of the force
is described by Coulomb's law. Also called
electrostatic force.

14. Stretch a rubber
band
After