Force is a kind of push or a pull on an object. The interaction of one object with another results in a force between the two objects. If a force acts on an object in the direction of its motion, then the object moves faster. If a force acts on an object opposite to the direction of its motion, then the objects slows down. Force may also change the direction of motion of an object. The effect of force changes with the direction of its application. Forces acting on an object in the same direction add to each other, while forces acting opposite to each other results in the difference of the forces.
The strength of force is called its magnitude. The international unit used to measure force is newton. A force can change the shape and size of an object. There are many types of forces.
The force resulting from the action of muscles is called muscular force. We make use of muscular force of animals like bullocks, horses and camels get our activities done. The point where force is applied on an object is called the point of contact. Friction is another type of contact force that always acts opposite to the direction of motion of the objects. Magnetic force and electro-static force are non-contact forces as they act on an object from a distance. The force of gravity is also a non-contact and an attractive force exerted by the earth on objects, due to which objects fall to the ground. Gravitational force is an attractive force between any two objects in the universe, and is a non-contact force.