# Types of Forces

Air Resistance Force

Air resistance force is the force of air pushing against a moving object. Air resistance force is a type of frictional force (refer to Chapter 5 of this unit). Like all frictional forces, the force of air resistance always opposes the motion of an object.

source: skwirk.com
Applied Force

An applied force is a force that is applied to an object by a person or another object. If a person is pushing a desk across the room, then there is an applied force acting upon the object. The applied force is the force exerted on the desk by the person.

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Frictional Force

Frictional forces are affected by the texture of the surfaces and the amount of force pushing them together. The angle and position of the objects affects the amount of frictional force. If an object is sitting flat against an object, then the frictional force is equal to the object's weight.

source: reference.com
Gravitational Force

But it turns out that in physics, there are really only four fundamental forces from which everything else is derived: the strong force, the weak force, the electromagnetic force, and the gravitational force.

source: study.com
Normal Force

Normal force is a contact force. If two surfaces are not in contact, they can't exert a normal force on each other. For example, the surfaces of a table and a box cannot exert normal forces on each other if they are not in contact.

Spring Force

Spring Force F spring: The spring force is the force exerted by a compressed or stretched spring upon any object that is attached to it. An object that compresses or stretches a spring is always acted upon by a force that restores the object to its rest or equilibrium position.

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Tension Force

Quick Answer. Tension force is a force that is exerted equally on both ends of a cable, chain, rope, wire or other continuous object and is transmitted between the ends by that object.

source: reference.com