- #1
member 529879
How exactly does the centrifugal force work? What causes it? Why is it considered a fictous force?
Demystifying Centrifugal Force: Causes, Mechanics, and Myths
- Thread starter member 529879
- Start date
However, in order to apply Newton's laws, a fictitious force called centrifugal force is often introduced to account for the observed motion. This force is equal and opposite to the centripetal force, allowing for the use of F=MA in a rotating reference frame.In summary, centrifugal force is a fictitious force that is used in rotating reference frames to account for the observed motion of objects and to allow for the use of Newton's laws. It is equal and opposite to the centripetal force and results from the change in momentum created by the centripetal force. This force is necessary in order to apply F=MA in a rotating, non-Newtonian space.
- #2
A.T.
Science Advisor
- 12,571
- 3,717
Did you read that?Scheuerf said:
http://en.wikipedia.org/wiki/Centrifugal_force_(rotating_reference_frame)
- #3
FactChecker
Science Advisor
Homework Helper
Gold Member
2023 Award
- 8,985
- 4,376
To an observer in stationary, Newtonian, space, objects fly out from the center of rotation just because they want to keep going in a straight line instead of circling around. No force is necessary to explain it. F=MA can be used the way Newton intended without dreaming up any new force. But an observer who is rotating and wants to apply F=MA in his rotating space, has to invent a force to explain why objects want to fly out from the center of rotation. Centrifugal force fits that need. He invents a force so he can use Newton's F=MA in his rotating, non-Newtonian space.
- #4
member 529879
Okay it's starting to make more sense now, but how is it that it points opposite the centripetal force and not in the direction of motion?
- #5
Vanadium 50
Staff Emeritus
Science Advisor
Education Advisor
2023 Award
- 35,005
- 21,683
Have you ever been spun quickly, like in an amusement park ride? In which direction do you feel a force?
- #6
FactChecker
Science Advisor
Homework Helper
Gold Member
2023 Award
- 8,985
- 4,376
The velocity is always tangential to the circle, so the bend in the velocity (the acceleration) is always toward the center. To make a free object take that turn, and not fly away straight, you must apply a centripetal force. That centripetal force is opposing the centrifugal force that tries to make the object fly away (actually just go straight away at the tangent velocity)Scheuerf said:
- #7
member 529879
Okay, I understand now that the centrifugal force opposes the centripetal force. But why exactly? If you imagine a car is rotating around a circular path in the labeled diagram below, the centripetal force is caused by static friction, and that people in the car will feel as if they are pushed to the left while turning. Can somebody explain why though that the friction is not opposing the path of inertia, and the centrifugal force is not in the same direction of the path of inertia.
Attachments
- #8
Khashishi
Science Advisor
- 2,813
- 492
People in the car will feel pushed to the right, not the left, (assuming you are looking down on them from above).
The path of inertia is a straight line. Friction between the wheels and the ground create a force on the car to the left (as viewed by the passengers). This is centripetal force. The passengers feel propelled to the right side of the car. The latter is centrifugal force.
The path of inertia is a straight line. Friction between the wheels and the ground create a force on the car to the left (as viewed by the passengers). This is centripetal force. The passengers feel propelled to the right side of the car. The latter is centrifugal force.
- #9
A.T.
Science Advisor
- 12,571
- 3,717
To make Newtons 2nd law work, as explained in post #3.Scheuerf said:
- #10
ulianjay
- 7
- 2
Centrifugal force is an inertial force that results from the change in momentum created by the centripetal force.
Think about when a car accelerates FORWARD but you feel a force pushing you BACK into your seat. That is the inertial force reacting the change in momentum of the car. Centrifugal force is the same thing, except it reacts the car's centripetal acceleration.
Look up D'Alembert's Principle for more reading on the topic of inertial forces.
Think about when a car accelerates FORWARD but you feel a force pushing you BACK into your seat. That is the inertial force reacting the change in momentum of the car. Centrifugal force is the same thing, except it reacts the car's centripetal acceleration.
Look up D'Alembert's Principle for more reading on the topic of inertial forces.
- #11
A.T.
Science Advisor
- 12,571
- 3,717
The inertial centrifugal force (in a rotating frame) acts on all objects, even those on which no real centripetal force is acting.ulianjay said:
- #12
ulianjay
- 7
- 2
A.T. said:
In a rotating reference frame all objects are by definition subjected to a centripetal acceleration. After all, a rotating reference frame is an accelerating reference frame (aka 'non-inertial') where the acceleration vector is centripetal.
- #13
A.T.
Science Advisor
- 12,571
- 3,717
Objects in rotating reference frames can have arbitrary accelerations, which are not necessarily centripetal.ulianjay said:
FAQ: Demystifying Centrifugal Force: Causes, Mechanics, and Myths
What is centrifugal force?
Centrifugal force is often described as the outward-pushing force that objects experience when rotating around a central point. However, it is not a real force, but rather a perceived force due to the tendency of objects to continue moving in a straight line, rather than following a curved path. It is a result of inertia and is also known as a fictitious force.
What causes centrifugal force?
The perception of centrifugal force is caused by the combination of two real forces: inertia and centripetal force. Inertia is the tendency of an object to maintain its state of motion, while centripetal force is the inward-pushing force that keeps an object moving in a circular path. Together, these forces create the illusion of centrifugal force.
How does centrifugal force affect objects?
The perceived centrifugal force does not actually affect objects directly. However, it can have an impact on how objects move and behave in a rotating system. For example, it can cause objects to feel like they are being pushed away from the center of rotation, and can also impact the shape of rotating objects.
Is centrifugal force a myth?
While centrifugal force is often referred to as a "myth," it is not entirely inaccurate. While it is not a real force, it is a useful concept for understanding how objects behave in rotating systems. However, it is important to recognize that it is not a true force, but rather a perceived one.
How can I better understand centrifugal force?
To better understand centrifugal force, it is important to have a good understanding of the principles of inertia and centripetal force. Additionally, studying examples of rotating systems and the forces at play can help clarify the concept. It is also helpful to remember that centrifugal force is a perceived force, rather than a real one.