How Is Centrifugal Force Calculated in Rotating Objects?

In summary, centrifugal force is a result of the momentum of an object being transferred to an opposing force.
  • #1
reddevil2576
54
0
i'm looking for some kind of formula for how much centrifugal force an object in motion has. for example i have a metal ring spinning x fast how much force is there. it a brake was applied to it so to speak how much force would be exerted on the break. i have a idea that is going to revolutionize space travel and make it possible for anyone.
 
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  • #2
F = dp/dt is all you need to know, where F = force, and dp/dt is change in momentum with respect to time.

How can you make space travel available to everyone when you don't even understand Newtons second law of motion?
 
  • #3
just because i don't understand the math doesn't mean i don't understand how it works i just don't know how to get figures so to speak. i don't understand the dp/dt thing can u explain that. i think i can convert centrifugal force to linear with my idea but i need to get the ring spinning so fast that my "brake" don't actually stop the centrifugal force.
 
  • #4
reddevil2576 said:
just because i don't understand the math doesn't mean i don't understand how it works i just don't know how to get figures so to speak. i don't understand the dp/dt thing can u explain that. i think i can convert centrifugal force to linear with my idea but i need to get the ring spinning so fast that my "brake" don't actually stop the centrifugal force.

dp/dt is the calculus representation for the change in momentun per unit time. p = mv is the linear momentum, with m = mass and v = velocity.

It would be good for you to find a basic physics book at your local library or bookstore, and spend some time learning the basics of mechanics. You don't necessarily need calculus to understand the most basic formulas and concepts. But at some point, it would be good for you to pick up differential and integral calculus, to help your understanding of basic physics better.

Will you be able to take physics and calculus soon? What year are you in high school?
 
  • #5
lol I'm out of high school. i didn't take any physics classes. I've started college for biochemistry but i had some financial problems so I'm waiting until i get this state job i applied for to go back. What does the d stand for?
 
  • #6
reddevil2576 said:
lol I'm out of high school. i didn't take any physics classes. I've started college for biochemistry but i had some financial problems so I'm waiting until i get this state job i applied for to go back. What does the d stand for?

The d stands for a differential, which is part of differential calculus. Here's a reasonable intro to differential calculus that starts with the basics:

http://en.wikipedia.org/wiki/Differential_calculus

A differential is a "change", so dp represents a change in momentum. But the differential is special, because when you write dp/dt, that means the change in momentum during a change in time, but you shrink the time interval infinitessimally small. That gives you the most accuracy, when you express dp/dt as a continuous function, just like the velocity as a function of time is continuous.

There are pretty good tutorials for mechanics, physics, calculus, etc. on the Internet. There's a good MIT video series as well... I'll see if I can find the link. It's listed over in the PF Learning Materials forum, I think...
 
  • #8
k i don't know if this formula is going to work for me then. I've been told that with physics its impossible to do what I'm trying to do but i don't see why its not possible and my ideas have been deleted off of here so i try not to talk about them on here. but I've seen videos on youtube of people successfully changing centrifugal force to linear ok i got a simpler version of my idea. if you have a metal ring let's say spinning at 1/4 of light speed and you have a "brake" so to say to act against it but not enough to stop it just to apply a force in a certain direction and on the opposite side of the ring you have something equally as powerful on the otherside acting to keep it going in the same dirrection as its already spinning. but if you put this picture in your head the left one acting against it will create an upwards force and the right one trying to keep it spinning acting against the other brake will have an upwards force as well but I'm imagining no where as near. I've talked to john Hutchinson he thinks my idea will work but he's the only other person that does.
 
  • #9
I do greatly appreciate your help by the way its very helpful
 
  • #10
reddevil2576 said:
k i don't know if this formula is going to work for me then. I've been told that with physics its impossible to do what I'm trying to do but i don't see why its not possible and my ideas have been deleted off of here so i try not to talk about them on here. but I've seen videos on youtube of people successfully changing centrifugal force to linear ok i got a simpler version of my idea. if you have a metal ring let's say spinning at 1/4 of light speed and you have a "brake" so to say to act against it but not enough to stop it just to apply a force in a certain direction and on the opposite side of the ring you have something equally as powerful on the otherside acting to keep it going in the same dirrection as its already spinning. but if you put this picture in your head the left one acting against it will create an upwards force and the right one trying to keep it spinning acting against the other brake will have an upwards force as well but I'm imagining no where as near. I've talked to john Hutchinson he thinks my idea will work but he's the only other person that does.

I remember a long time ago, I was trying to come up with a mechanism that would do something similar -- convert rotary motion and energy into linear motion. The problem is that for an isolated system (nothing goes in or out), momentum is conserved and cannot change. So, whatever your linear momentum is to start (p=mv), that's what you are stuck with, no matter what you do in that closed system. The only reason rockets can fly through space, is that the fuel that they burn ejects mass out the nozzle. This shoots some mass one way, and the mass of the rocket goes the other way.

So any trick that you could think of to convert isolated rotational motion into isolated linear motion, would violate the conservation of linear momentum principle. And that is extremely unlikely/impossible.

That's why it is good to learn as much real math and physics as you can, so that you don't waste any brain cycles on something that is basically impossible. That frees up brain cycles to work on hard science problems that *may* be possible, and believe me, there is plenty of room for invention and innovation in the realm of real science.
 

FAQ: How Is Centrifugal Force Calculated in Rotating Objects?

How much centrifugal force is exerted by a spinning object?

The amount of centrifugal force exerted by a spinning object depends on its mass, speed, and distance from the center of rotation. The formula for calculating centrifugal force is Fc = m * v^2 / r, where Fc is the centrifugal force, m is the mass of the object, v is its linear velocity, and r is the distance from the center of rotation. The larger the mass and velocity of the object, or the smaller the distance from the center of rotation, the greater the centrifugal force.

How is centrifugal force different from centripetal force?

Centrifugal force is the outward force felt by an object moving in a circular path, while centripetal force is the inward force that keeps the object moving in that path. Centripetal force is necessary to counteract centrifugal force and maintain the circular motion. Centripetal force is typically provided by tension, gravity, or another force acting towards the center of rotation.

What are some examples of centrifugal force in everyday life?

Centrifugal force can be observed in many common situations, such as when a car turns a corner and passengers feel pulled towards the outside of the turn, or when wet clothes in a washing machine stick to the sides as they spin. Other examples include a spinning top, a merry-go-round, or a planet orbiting around a star.

Can centrifugal force be greater than gravity?

Yes, centrifugal force can be greater than gravity in certain situations. For example, astronauts in orbit around Earth experience weightlessness because the centrifugal force of their orbit cancels out the force of gravity. However, on Earth's surface, gravity is always the dominant force and prevents objects from being thrown off into space due to centrifugal force.

How does centrifugal force affect the shape of planets and other celestial bodies?

Centrifugal force plays a role in shaping the appearance of planets and other celestial bodies. For instance, the Earth is not a perfect sphere, but rather slightly flattened at the poles and bulging at the equator due to the centrifugal force of its rotation. Similarly, gas giants like Jupiter and Saturn have a more oblong shape because of their rapid rotation.

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