Centrifugal force

I am having problems explaining the a certain group of inanic acquaintences that just can't understand that centrifugal force, is a fallacy. I have explained centripetal force and newtons first law, but they still don't get it. could any of you help me here?
The 'centrifugal' force is the change in inertia that the body feels as the centripetal force changes its direction.
Tell them that the centrifugal force is not real in the same sense that the force which pushes you back in your seat (in a dragster, for example) is not a real force. Its inertia.


Science Advisor
Homework Helper
Gold Member
Like Crosson. Tell them about the easily understood exemple of when a car breaks suddenly. There is no force pushing the passengers foward. It's the car that has suddenly stopped but the passengers keep on going due to inertia. Then say that the centrifugal force is the same principle: when the car turns, it is rectifying its trajectory, but since the passengers are not submitted to any force, their trajectory remains unchaged (first law).
thankyou all - I tried explaining it to them that way, but thay have better sources....wikipedia - according to them...its a "resultant force" oh well, they will only look stupid for the rest of their lives.


Gold Member
My father, the Geography teacher also doesn't get it.

Some day, I am going to build a demo to debunk the myth using a bicycle wheel and a marble.
Tell them that some minds prefer to run around in a small, comfortable circle, and that they are kept from running into themselves by the centrifugal force, while other minds think straight, in which case a centrifugal force is not required.

hahaha, I will post that there. Here is the link, if you would like. None of them give me any respect there - I am a 18 year old, professional woodwind repair technician - they are all hobbyists. Denial, I think, or perhaps impotism?

Not to mention, you can't even begin to expect them to be able to understand newton's third!!! Let alone, any other aspect of physics. Not that I am some junior stephen hawking or anything. but hey, it is just sad when people in their 30's to 70's still argue with fact.
that's because physics is STILL not a required course even in high schools across america! Let us rejoice.... :frown:
In defense of the less gifted we need to remember that Physics 101 used to teach people that there was such a thing as Centrifugal Force. Look at it this way: Centrifugal Force is just a name that was given to the very specific inertial "force" required to be overcome when a body in motion is forced to accelerate in a direction perpendicular to that of its straight line motion. We gave the name Centrifugal Force to this seemingly apparent but non-existant force because we could "feel it" when we swing a mass around. Things that we do not understand we tend to put into little boxes and give them cute names to maintain the impression that we understand and control things around us. For example: the Devil, or God, or Gravitrons. Things that do not exist but we have a need to believe in because without them we would have to admit that we do not know it all yet.


P.S. There is nothing wrong in Believing if it makes Your World a better one.

Tell them that the centrifugal force is only a term you get in Newtons second law when you use a rotating reference frame. When you switch to a stationary reference frame there is no need for a centrifugal force.

Want to reply to this thread?

"Centrifugal force" You must log in or register to reply here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving