We already know the definition of force as the push or pull experienced by an object when it interacts with another object which results in the change of state, either from rest or from uniform motion. The application of force can also result in the change of the shape of the object. Force is classified into two types, which are contact force and non-contact force.
When you jump, you always return to the surface. Why? Is there anything that is holding your feet when you try to jump? When you throw a ball high up in the air, it reaches the highest point, and then it was invariably returned to its thrower on the ground. These occurrences can be explained by the non-contact force.
For a quick recap of what is force and its types, watch the below video:
What is Non-Contact Force?
A non-contact force is a force applied to an object by another body that is not in direct contact with it. Non-contact forces come into play when objects do not have physical contact between them or when a force is applied without any interaction. When compared to the types of contact forces, there are very few non-contact forces.
Non-Contact Forces Types
Gravitational force is responsible for bringing the items we toss into the air back to earth. When an object is resting on a surface it is exerting a downward force equal to its weight and this downward force is known as Gravitational force.
The gravitation is a force of attraction that exists between all bodies that have mass. The gravitational force of the sun keeps the Earth and all the other planets of the solar system is a fixed orbit. Gravitational force does not need to be in contact to exert its downward force.
The electrostatic force is very similar to the gravitational force, the difference here is that gravitational force acts between masses and an electrostatic force acts between two charged bodies.
If you rub a comb on your clothes and then hold it near tiny pieces of paper you will see the bits of paper standing on their end attracted to the comb. We are made of tiny positive, negative and neutral particles. The opposite charges attract each other and like charges repel. This is the result of electrostatic forces.
Have you ever used a magnet? Doesn’t it feel like magic? If you ever have two magnets, try joining their ends. In one case, the ends will attract each other vigorously. In another case, no matter how hard you try, the ends will never make contact.
Even if you push the ends together, the second you leave it, it will bounce off. This is the result of Magnetic force. It is also responsible for the attraction of iron by a magnet. The magnetic force exerted by a magnet decreases with the increase in the distance from a magnet. Read what is a Force and other types of forces like Contact Force.
Examples of Non-Contact Force
- An apple falling down from a tree is one of the best examples of non-contact force.
- Iron pins attracted in the presence of a magnet bar without any physical contact.
- Falling of raindrops on earth is also an example of non-contact force.
- The charging of the hair and attraction of paper bits towards it.
- Two magnets are placed close to each other is also a non-contact force example.
- The freefall of a ball towards earth is by the virtue of gravity.
- Leaves falling from a tree is an example of non-contact force.
- Electromagnetism is another example of a non-contact force.
- There are various examples from electrostatics showing the attraction of small materials towards an object.
- When an electric current is passed through iron converting it into an electromagnet, it attracts iron and particles towards it, thus, displaying non-contact force properties.
Difference between Contact and Non-Contact Forces
|Contact forces||Non-contact force|
|Contact force occurs due to the contact between two different objects.||Non-contact force occurs due to either attraction or repulsion between two objects such that there is no contact between these objects.|
|There is no field linked with the contact force.||There is always a field linked with non-contact force.|
|The frictional force is an example of a contact force.||Gravitational force is an example of a non-contact force.|