What aren't all new rigs made "freefly" friendly?

[Tonto 1]

ROL?

t

It's the year of the Pig.

[FliegendeWolf 0]

Quote

Just so you know there is no such thing as centrifugal force. There is inertia which is commonly thought of as "centrifugal force" and there is centripital force which is center seeking force. What you expirence as "centrifugal" is just interia trying to keep its path and an outside force constantly changing its bath, pushing you away from the center.

Just thought you might want to know.

I was flabbergasted when my physics teacher explained this to us. Eventually, I understood the principle, but what I've never understood is why so few people know this. I could swear that I "learned" about centrifugal force in school, and I know for a fact that I "learned" about it in different science museums.

Why does the concept of centrifugal force continue to get propogated when it is completely untrue? How can there be nobody in the know at a science museum for cripes sake?

A One that Isn't Cold is Scarcely a One at All

[rigging65 0]

Quote

I've got my pullout set up so I can change between throwout and pullout in about 1 minute, so I tend to opt towards the throwout when I fly my suit, but you certainly can jump a wingsuit with a pullout safely.

--------------------------------------------------------------------------------



Interesting, can you give us a description of your system?

I have a loop sewn into the base of my p/c. Then I have a PUD/lanyard/pin assembly with a grommet tab hanging off it (imagine a regular PUD assembly, then just sever the grommet tab loose from the p/c base). The end of the grommet tab is also a web loop, so I can larkshead it to the p/c base and make a pullout.

At the apex of the p/c I have a soft, flat PUD handle sewn in place of a hackey. Since it's soft and flat, I can pack it right into the container without any real bulk.

And away you go...

"...and once you had tasted flight, you will walk the earth with your eyes turned skyward.
For there you have been, and there you long to return..."

[smooth 0]

Quote

ROL?

t

Rear of Legstrap

[Watcher 0]

Well it starts in elementary school when the teachers are more like moms and while they do have teachers certificates (and some have degrees) many that settled on primary education did not recieve a higher level physics class that explained mechanics in great detail. Add to this that many parents answer the same question to kids when the kid ask how they stay on the roller coaster without falling out or how does a swing work. The grew up with "centrifugal" force.

I would say its not until recently have schools started pushing a higher level of education. That college is starting to become mandatory for many entry level jobs and advancement requires a degree. So now I think more people are being educated but like you said its hard to break the chain. Many people do not realize they have been misinformed, and hell others just go into denial, your shaking the foundation of something they have believed in since they were 4.

Education is the key, which is why whenever I see or hear someone use "centrifugal" I try to explain how its really the concept of Inertia and you are confusing the word centripital which actually has the opposite meaning.

Force Diagrams are cool

--

Jonathan Bartlett
D-24876
AFF-I

[billvon 3,109]

>I could swear that I "learned" about centrifugal force in school, and I
>know for a fact that I "learned" about it in different science museums.

Claiming that there is no such thing as centrifugal force is like claiming there is no such thing as force felt from acceleration (it's just normal force as a result of inertia) no such thing as freefall (you are never drag-free in normal skydiving) and no such thing as G-forces in a hard pullup (again, just normal force and inertia.) All technically correct, but as engineers often design for all those things (and have their systems/aircraft/parachutes work) they are all useful abstractions.

[FliegendeWolf 0]

Well...except that "centrifugul force" is not a force at all, as an object moving in a circle is not being accelerated away from the circle's center. Since there is no acceleration, there can be no force. The correct term for the phenomenon that keeps water in a spinning bucket is "tangential velocity," which is entirely accurate and no more difficult to abstract than is the concept of centrifugul force.

The simple evidence is that when you let go of the bucket of water, it does not move straight out from the center of the circle but continues to move tangentially.

A One that Isn't Cold is Scarcely a One at All

[billvon 3,109]

>as an object moving in a circle is not being accelerated away from
>the circle's center.

No, it's being accelerated _towards_ the circle's center. Thus anyone on that object feels an equivalent normal force that we call centrifugal force.

If you could stand inside a space shuttle external tank right after it was jettisoned, you'd be pretty close to freefall. No significant force would be acting on you. If you spun it, and you stood on the edge of the tank, you would feel a force holding you to the floor. Hence, the common term centrifugal force. It is an apparent force that causes objects to accelerate towards the outside of the tank.

Now, of course, to an outside observer the object you have released isn't moving at all; it remains on a constant vector until the wall of the spinning tank "rises up" to meet it. However, this does not invalidate the force to the inside observer. He still feels it.

>The correct term for the phenomenon that keeps water in a spinning
> bucket is "tangential velocity,"

If you let go of the bucket, it would indeed have a constant tangential velocity at that point. Since you are applying force to the bucket, that velocity vector is constantly changing. A change in velocity means an acceleration. We perceive acceleration as force, hence the term centrifugal force. Its converse is centripedal acceleration, which is where that apparent force comes from.

[dreamsville 0]

I misstated. Although I have taken physics, the nuances escaped me in the heat of the moment (no pun intended).
|

I don't drink during the day, so I don't know what it is about this airline. I keep falling out the door of the plane.

Harry, FB #4143

[Tonto 1]

Already gone the route of the bellyband here... BOC or pullout. No Pullout for birdman,

t

It's the year of the Pig.

[FliegendeWolf 0]

Quote

>as an object moving in a circle is not being accelerated away from
>the circle's center.

No, it's being accelerated _towards_ the circle's center. Thus anyone on that object feels an equivalent normal force that we call centrifugal force.

If you could stand inside a space shuttle external tank right after it was jettisoned, you'd be pretty close to freefall. No significant force would be acting on you. If you spun it, and you stood on the edge of the tank, you would feel a force holding you to the floor. Hence, the common term centrifugal force. It is an apparent force that causes objects to accelerate towards the outside of the tank.

Now, of course, to an outside observer the object you have released isn't moving at all; it remains on a constant vector until the wall of the spinning tank "rises up" to meet it. However, this does not invalidate the force to the inside observer. He still feels it.

>The correct term for the phenomenon that keeps water in a spinning
> bucket is "tangential velocity,"

If you let go of the bucket, it would indeed have a constant tangential velocity at that point. Since you are applying force to the bucket, that velocity vector is constantly changing. A change in velocity means an acceleration. We perceive acceleration as force, hence the term centrifugal force. Its converse is centripedal acceleration, which is where that apparent force comes from.

Indeed, the object is being accelerated toward the center of the circle, but this is the only acceleration acting upon the object to produce the velocity changes.

The key words you use are "apparent force." There is only one "actual" force acting upon the object, and that is the force that keeps the object moving in a circle. The amusement park visitors riding the Rotor or the Gravitron may feel like there is a force pushing them against the walls, but it is not a force, but rather the effects of the inertia of the constantly changing velocity acted upon by the centripetal force.

Consider the possibility that there is both a centrifugal (CF) and a centripetal (CP) force acting upon an object (X) moving at a constant speed (S) (not velocity):

<----CP X CF---->
S
|
|
V
These two forces will cancel each other out, causing X to continue at speed S along the vector in the diagram. Thus, the presence of both a centrifugal and centripetal force will produce a constant velocity.

A One that Isn't Cold is Scarcely a One at All

[JeffGordon 0]

Rear Of Leg