Types of Forces | Science

Types of Forces

1. Contact forces – forces where objects touch or contact with each other.

     * Applied forces – a force given to a person or object by another person or object.

     * Friction forces – is the force acting against or opposite an object in contact with which makes the movement of the object slow down. Friction always opposes the motion of an object.

     * Normal forces – is the force that acts perpendicular to the surface of the object in contact with.  Its symbol is Fn.

     * Tension forces – is the force applied to string, rope, chain, or cable. Its symbol is T.

2. Non-contact forces – forces where objects do not touch or contact with each other. These forces act over a zone or area called a field.

     * Gravitational forces – is the force of attraction between two objects. In the case of the Earth, this gravitational force causes objects to fall down to the ground. It makes satellites and smaller objects stay in orbit near the more massive planets. Mass and distance of the two objects affect the gravitational force that holds them. The bigger the masses of the objects are, the bigger is the gravitational force between them. The closer the objects are, the greater is the gravitational force between them. The figure below illustrates gravitational force between the Earth and the Moon. Earth has bigger gravitational force over the Moon.

     * Magnetic forces – are forces exerted on a field of attraction or repulsion as in the case of magnets and other magnetic materials. Magnets and magnetic materials have two poles – the north and south poles. Attraction may occur when two poles are not the same, a positive and a negative while repulsion takes place with the same poles, positive-positive and negative-negative.