Centrifugal Force?

In this month's SciAm, there is an article about tethered satellites. In the
article they mention more then once about using centrifugal force. I am
utterly confused. Help a physics newb out. I thought centripetal was a
force, and centrifugal was an effect.

BV.

On 7/15/2004 07:02, Benign Vanilla wrote:

In this month's SciAm, there is an article about tethered satellites. In the
article they mention more then once about using centrifugal force. I am
utterly confused. Help a physics newb out. I thought centripetal was a
force, and centrifugal was an effect.

BV.



How about the dictionary?

centrifugal force n - the force that tends to impel a thing or parts of
a thing outward from a center of rotation;

centripetal force n - the force needed to constrain a body to a circular
path;

On 7/15/2004 07:02, Benign Vanilla wrote:

In this month's SciAm, there is an article about tethered satellites. In the
article they mention more then once about using centrifugal force. I am
utterly confused. Help a physics newb out. I thought centripetal was a
force, and centrifugal was an effect.

BV.



How about the dictionary?

centrifugal force n - the force that tends to impel a thing or parts of
a thing outward from a center of rotation;

centripetal force n - the force needed to constrain a body to a circular
path;

"Mark Hansen" wrote in message
...
On 7/15/2004 07:02, Benign Vanilla wrote:

In this month's SciAm, there is an article about tethered satellites.
In the
article they mention more then once about using centrifugal force. I
am
utterly confused. Help a physics newb out. I thought centripetal was a
force, and centrifugal was an effect.

BV.
It is a commonly used 'incorrect notation'.


How about the dictionary?

centrifugal force n - the force that tends to impel a thing or parts
of
a thing outward from a center of rotation;

centripetal force n - the force needed to constrain a body to a
circular
path;
The 'point' is that there is (technically), no such thing as 'centrifugal
force'. It is the result of inertia, wanting the object to carry on in a
straight line, and applying centripedal force to this object to pull it
into a curved path. However it is a very commonly used 'shorthand' for
this situation. The dictionary you quote, is not correct. A technical
dictionary, instead gives:
Centrifugal force - see centripetal force.
Centripetal force - A force applied to constain a body into a curved path.
The reaction to this force, is sometimes (in mechanics), referred to as
'centrifugal force', however this is only the reaction to the real force
being applied.

Look at:
http://www.moo.uklinux.net/kinsler/i...ntrifugal.html

Best Wishes

"Mark Hansen" wrote in message
...
On 7/15/2004 07:02, Benign Vanilla wrote:

In this month's SciAm, there is an article about tethered satellites.
In the
article they mention more then once about using centrifugal force. I
am
utterly confused. Help a physics newb out. I thought centripetal was a
force, and centrifugal was an effect.

BV.
It is a commonly used 'incorrect notation'.


How about the dictionary?

centrifugal force n - the force that tends to impel a thing or parts
of
a thing outward from a center of rotation;

centripetal force n - the force needed to constrain a body to a
circular
path;
The 'point' is that there is (technically), no such thing as 'centrifugal
force'. It is the result of inertia, wanting the object to carry on in a
straight line, and applying centripedal force to this object to pull it
into a curved path. However it is a very commonly used 'shorthand' for
this situation. The dictionary you quote, is not correct. A technical
dictionary, instead gives:
Centrifugal force - see centripetal force.
Centripetal force - A force applied to constain a body into a curved path.
The reaction to this force, is sometimes (in mechanics), referred to as
'centrifugal force', however this is only the reaction to the real force
being applied.

Look at:
http://www.moo.uklinux.net/kinsler/i...ntrifugal.html

Best Wishes

"Mark Hansen" wrote in message
...
snip
How about the dictionary?

centrifugal force n - the force that tends to impel a thing or parts of
a thing outward from a center of rotation;

centripetal force n - the force needed to constrain a body to a
circular
path;

Yeah, uh...been there, done that. My point is that I do not believe
centrifugal force to be accurate. As I was taught, it is an effect, not a
force. So your definition, by my understanding is as erroneous as the SciAm
article.

BV.

"Mark Hansen" wrote in message
...
snip
How about the dictionary?

centrifugal force n - the force that tends to impel a thing or parts of
a thing outward from a center of rotation;

centripetal force n - the force needed to constrain a body to a
circular
path;

Yeah, uh...been there, done that. My point is that I do not believe
centrifugal force to be accurate. As I was taught, it is an effect, not a
force. So your definition, by my understanding is as erroneous as the SciAm
article.

BV.

From BV:

I thought centripetal was a force, and
centrifugal was an effect.

Exactly. Centrifugal `effect` is very real, while the actual working
force is centripetal. When you swing a ball on a string around your
head, the string is exerting the force.

The dictionary definition which Mark Hansen cites is tied to the
'popular concept' called centrifugal force. That's understandable
considering the technical complication that'd arise explaining how the
'real' force is not centrifugal but center-ward, and then 'centripetal'
would have to be defined under the same heading.
The SciAm article no doubt uses 'centrifugal force' in the
same popular vein. oc

From BV:

I thought centripetal was a force, and
centrifugal was an effect.

Exactly. Centrifugal `effect` is very real, while the actual working
force is centripetal. When you swing a ball on a string around your
head, the string is exerting the force.

The dictionary definition which Mark Hansen cites is tied to the
'popular concept' called centrifugal force. That's understandable
considering the technical complication that'd arise explaining how the
'real' force is not centrifugal but center-ward, and then 'centripetal'
would have to be defined under the same heading.
The SciAm article no doubt uses 'centrifugal force' in the
same popular vein. oc

"Benign Vanilla" wrote in message
...
In this month's SciAm, there is an article about tethered satellites. In
the
article they mention more then once about using centrifugal force. I am
utterly confused. Help a physics newb out. I thought centripetal was a
force, and centrifugal was an effect.

BV.

Hey BV

In order to clarify, you need to ask yourself "An effect of what?"

It's perfectly valid to speak of a centrifugal force as long as we ...

.... *** always remember and never forget *** ...

.... that centrifugal force is a "fictitious force", also known as an
"inertial force" because the underlying cause is the inertia of a body as
viewed from a non-inertial frame of reference. It is sometime convenient to
view a situation from a non-inertial frame of reference, however if we wish
to deal with said situation in a nice Newtonian way, it becomes necessary to
introduce "fictitious forces" in order to explain the strange behaviour of
the things we are looking at. The effects of such "fictitious forces" are
real enough because of the underling cause, but they are not fundamental.