Force can be divided into two categories:
- Contact Force
- Non-Contact Force.
Contact Force
A contact force can be defined as any force that results when a being or object is in physical contact with another object. All mechanical forces are contact type forces. Contact forces can be of many types.
Types of Contact Force
Normal Force
When an object is lying still on another object or surface, the surface is exerting an upward force to support the weight of the object. This force exerted by the surface to support the force exerted by the object is known as the normal force.
Applied Force
When a force is applied on an object by a person or another object it is known as applied force. For example, if a person is pushing a box around a room then the force exerted by that person to move the box will be the applied force.
Frictional Force
Frictional force can be defined as the resisting force acting between the object and the surface on which the object is trying to move. Friction results from the movement of two surfaces which are pressed together closely.
Air Resistance Force
When an object move through air it experiences a frictional force acting upon it. This force is resistive in nature and is known as air resistance force.
Tension Force
When a rope, wire or string is pulled tightly at both the ends a force is transmitted through it. This force is known as tension force.
Spring Force
A force exerted by a spring which is stretched or compressed on an object is known as spring force.
Non-contact Force
Force which is exerted without requiring contact with the object is known as non-contact force.
Types of Non-contact Force
Gravitational Force
It is defined as the force of gravity by which moon, earth or other massively large objects attracts another objects. According to Newton’s Law of gravity “gravitational forces between two bodies are directly proportional to the product of their masses and inversely proportional to the square of the distance between them”.
Magnetic Force
Magnetic force can be defined as the attraction or repulsion between electrically charged particles because of their motion. It exists without any contact between objects.
Electrostatic Force
Electrostatic force is the force exerted by all electrically charged bodies on another charged bodies in the universe.