Centrifugal force


The centrifugal force is the apparent force when it swings out of a dough. You can think of a ball at the end of a string being twisted, or the outward motion you feel when turning a curve while riding in a car. In an inertial frame , there is no external acceleration since the system is not rotating. The ball or your body simply moves in the straight line that they were originally following. But in the rotating frame of reference of the rope or the car, they seem to accelerate .

  • Unit:  Newton
  • Symbol:  N
  • Formula: Fcf = mw 2 r

What is centrifugal force?

It is a force that arises when the movement of a body in a rotational system is described , or the apparent force perceived by a non- inertial observer who is located in a rotating reference system .

  • What is centrifugal force?
  • How it is calculated
  • Units
  • Applications
  • Importance of centrifugal force
  • Examples

What is centrifugal force?

Centrifugal force is the force that is produced out of a mass when it rotates. Taking into account that the Earth rotates around a fixed axis , the direction of the centrifugal force always moves away from the axis, it is opposite to the direction of gravity at the equator ; and at the poles of the Earth it is zero . It is the necessary inward force that prevents the mass from moving in a straight line , it has the same size as the centrifugal force, with the opposite sign. It is important to mention that the centrifugal force is only an apparent force .


How it is calculated

Centrifugal force can be calculated when you know exactly the mass and speed of the object, as well as the radius of the circle in which it is traveling. Then we have that the formula to calculate the centrifugal acceleration is the following:

Ac = V 2 / R

Formula in which:

  • Ac:  centripetal acceleration
  • V = tangential velocity
  • R = radius of gyration

You can also add the following data:

  • V = ω R

What is the angular velocity or ω and that it is measured in radians / second , which we must multiply by the R, which means radius .

General Formula

Fcf = mw 2 r


Centrifugal force can generally be measured associated with a particle of mass that is in motion (m). For example, in a laundry centrifuge, this particle of mass could be taken as the density of the components of said centrifuge, which are water and clothes.

It can then be measured by the speed of said movement which is known by the name of angular velocity and is represented by the letter ” w “ . On the other hand, evidently a position in the plane of rotation (r) that would be the corresponding radius from the center of rotation to where the container on this occasion allows the clothes to be reached, in the case of the washing machine.

Its general formula is equal to  Fcf = mw 2 r  to finally be able to be expressed in the corresponding Newton (N) force measure .


The main applications where centrifugal force is used are the following:

  • The inclination in the curves of the train, since the centrifugal force that drives the train out when it takes the curve, is counteracted by the force that is manifested when the side of the wheels presses on the rails.
  • It is used in the centrifuge, which is a machine that rotates a sample to accelerate the decantation or sedimentation of its components.
  • In centrifugal pumps and turbines that work with liquids and air, respectively.
  • In the casting of metals , for accuracy, safety and quality of the castings.
  • In water pumps since they rotate the water around in the turbine so that it is expelled through its corresponding opening, taking the water to the place it is needed.

Importance of centrifugal force

In physical and chemical studies there is a special method used for the separation of elements , whether they are liquid or not. This has the purpose of studying its composition through a physical process that is called centrifugation .

The centrifugal force is also responsible for making rotary circular movements by means of circular energy causing the elements to be attracted towards a center and in this way they can be separated from the other substance .

It is for this reason that centrifugal force is a very important process that separates and decomposes chemical samples . The results that are made using this process are used for the studies of the elements applied in the centrifuge . The importance of this method lies in the infinite uses it has in the different areas of physics and chemistry for the separation and union of mixtures.

It is then used in fields such as pharmaceutical , the organic chemistry , the chemical basic, the food , the nucleare studies s and appliances appliances that need the process of filtration .


Some examples of centrifugal force are as follows:

  • The rotation of the planets : because in it you can see the centrifugal force that occurs in the elliptical rotation that the planets have with respect to their star . An example of this is our planet earth .
  • Washing machine : when we put our clothes to wash in our washing machine, it is very easy to observe the centrifugal force.
  • Blender : when the blender is running you can see the centrifugal force. When we make a fruit smoothie with milk you can appreciate the strength even better.
  • When we observe the mud that is thrown from a tire or when we see the children that they feel a force that pulls them out when they play on the carousel .

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