Can we model fictitious forces using vectors?

In summary, the conversation discusses the concept of centrifugal force and its relationship to centripetal force in the context of a spinning yo-yo or a Ferris Wheel. The concept of centrifugal force is introduced as a fictitious force that pushes objects outwards, while centripetal force pulls them towards the center. However, in the case of a spinning yo-yo, there is no need to invoke centrifugal force as the observer is in an inertial frame. The use of centrifugal force is only necessary in rotating reference frames to reconcile with Newton's laws.
  • #1
flyingpig
2,579
1

Homework Statement



Let's say that you are on a Ferris Wheel or you are spinning a Yo-yo horizontally in a circle. There is a fictitous force known as centrifuge force that is pushing the car or yo-yo outwards.
However, the centripetal force that is keeping it in tact, is a vector pointing towards the center. We know that F [tex]\alpha[/tex] a, so even though centrifuge is a fictitious force, how come the "vector" of it is opposite to that of centripetal acceleration?

The Attempt at a Solution



I have been pondering this question for 3 days...

For the yoyo case, would to be just the tension?

T = [tex]\stackrel{mv²}{r}[/tex]

Also, I read a proof on how centripetal acceleration is derived, but why do we always neglect the negative sign in the formula a = [tex]\stackrel{-|v²|}{r}[/tex]
 
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  • #2
Ignoring the rotation of the Earth itself you are an inertial observer when you look at a spinning yo-yo. There is no need to invoke a centrifugal force in this case. There is no centrifugal force in this case.

Centrifugal force are needed to force-fit Newton's laws to the domain of rotating reference frames (a domain in which Newton's laws do not truly apply).
 
  • #3
D H said:
Ignoring the rotation of the Earth itself you are an inertial observer when you look at a spinning yo-yo. There is no need to invoke a centrifugal force in this case. There is no centrifugal force in this case.

Centrifugal force are needed to force-fit Newton's laws to the domain of rotating reference frames (a domain in which Newton's laws do not truly apply).

Ferris Wheel case?
 
  • #4
So I still don't get it...
 
  • #5
?

I can provide a response to this question by explaining the concept of fictitious forces and their relationship with vectors.

Fictitious forces are forces that appear to act on an object in a non-inertial reference frame, but are actually due to the acceleration of the reference frame itself. In the case of a Ferris Wheel or a yo-yo, the object is moving in a circular motion and therefore experiencing a centripetal acceleration towards the center.

The centrifugal force, also known as the centrifuge force, is a fictitious force that appears to push the object away from the center of the circular motion. This force is not a real force, but rather a perceived force due to the object's inertia wanting to continue moving in a straight line while the reference frame is accelerating towards the center.

Now, in terms of vectors, we know that forces are vectors and therefore have both magnitude and direction. The direction of a force is determined by its effect on the motion of an object. In the case of the centrifugal force, it appears to push the object away from the center, which is in the opposite direction of the centripetal acceleration. This is why the vectors for these two forces are opposite to each other.

As for the formula for centripetal acceleration, the negative sign is often neglected because it is already implied in the direction of the vector. The magnitude of the centripetal acceleration is always positive, and the direction is determined by the direction of the velocity vector. Therefore, the negative sign is not necessary to include in the formula.

In conclusion, we can model fictitious forces using vectors by understanding their relationship to the acceleration of the reference frame and the direction of their effects on the motion of an object. The negative sign in the formula for centripetal acceleration is often neglected because it is already implied in the direction of the vector.
 

Related to Can we model fictitious forces using vectors?

1. What are fictitious forces?

Fictitious forces are forces that appear to act on objects, but are actually the result of non-inertial reference frames. These forces are not caused by any physical interactions, but rather by the motion of the observer or the object in a non-inertial frame.

2. Can fictitious forces be modeled using vectors?

Yes, fictitious forces can be modeled using vectors. In fact, vectors are the preferred mathematical tool for representing and analyzing fictitious forces. Vectors allow us to accurately describe the magnitude, direction, and location of fictitious forces in a non-inertial reference frame.

3. How do we calculate fictitious forces using vectors?

To calculate fictitious forces using vectors, we first need to identify the non-inertial reference frame in which the force is acting. Then, we can use the laws of motion and the principles of vector addition and subtraction to determine the magnitude and direction of the fictitious force. This process may vary depending on the specific situation and the type of fictitious force involved.

4. What are some examples of fictitious forces?

Some common examples of fictitious forces include centrifugal force, Coriolis force, and the centrifugal force experienced by a person in a rotating reference frame. Other examples include the force experienced by an object on a rotating merry-go-round and the force on a car as it goes around a sharp turn.

5. Why is it important to model fictitious forces using vectors?

Modeling fictitious forces using vectors allows us to accurately describe and analyze the motion of objects in non-inertial reference frames. It also helps us understand the underlying principles behind these forces and how they affect the behavior of objects. Additionally, using vectors allows us to make predictions and calculations that can help us in engineering and other practical applications.

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