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Centrifugal Force

Understanding the Concept of Centrifugal Force Made Easy

What is centrifugal force? How can it be measured? What are its characteristics? Let's find the answers to these and many other questions regarding this particular concept of physics.
ScienceStruck Staff
Last Updated: Mar 8, 2018
Dry Centrifugal Machine
The phenomenon of centrifugal force is a concept of physics. This concept has been framed to explain the force which is created when an object is in rotation, as well as to elucidate, what keeps an object, when set in a rotational motion, moving in circles for sometime before coming to a standstill. The term centrifugal has been coined by combining two distinct Latin words - centrum (meaning center and fugere (meaning to escape) - together. Therefore, it can be roughly defined as a force which escapes from the center of a rotating body in an outward direction, while the object is in circular motion. In turn, this outward force keeps the object moving in a circular motion for sometime, before it becomes stationary again.

Definition

As mentioned above, it is the force created when an object is in rotational motion, and this force spreads in an outward direction, causing the central point or axis (imaginary central part) of the object, to experience an inertia-like state. As per its scientific definition, centrifugal force represents the effects of inertia that arise in connection with rotation and which are experienced as an outward force away from the center of rotation. A very good example of this phenomenon is the hammer throw competition in athletics events. As the athlete starts to swing the heavy hammer in circular motion, the centrifugal force coming from the center of this circle of velocity, that is from the body of the athlete, towards the head of the hammer, causes the motion of the hammer to gain momentum, and when it is released, this momentum is responsible for making the hammer land far away from the athlete, while still in rotational motion.

Two Distinct Concepts

There are two distinct concepts of this force - fictitious and reactive centrifugal force. Fictitious centrifugal force defines the force that is produced during the phenomenon of a circular motion, which takes place in a non-inertial reference frame. For instance, the outward force that emanates from the core due to rotation of planets on their own axes, is a case of fictitious type. On the other hand, reactive centrifugal force is a force that is the result of the centripetal force that occurs when an object is moving along a curved path. While accelerating towards the mean location of the curve, an object also, invariably, accelerates towards its own mean location or axis. A good example would be a ball that is rolling along a curved path. While moving towards the curve, the ball is also undergoing rotation on its imaginary axis. The revolution of planets around the sun while continuing to rotate on their respective axes is another good example of reactive type.

Calculation

Centrifugal force can be calculated by the using the following equation as a formula:-

Fcf = +mv2 / r = +mrw2

where:
  • Fcf = centrifugal force
  • m = mass of the object that is in rotation
  • v = linear velocity of the rotating object
  • r = radius of the curvature
  • w = angular velocity of the moving object
Another question may arise with reference to relative centrifugal force. Well, it is simply a multiplier for the force of gravity during rotation. It may be expressed as a value of the strength, or number of times the force of gravity, with relation to centrifugal force that acts on the object in question.

That was a brief overview of what centrifugal force implies and how it can be calculated in terms of mathematics to derive a numeric value for purpose of measurement or comparison. This concept is often confused with centripetal force. While the former describes the force of motion that emanates from within the object's core, in an outward direction, the latter describes the force that is created (and which propels the object along), when an object is moving along a curved pathway.