WRT: http://groups.yahoo.com/group/mukto-mona/message/48059
Subimal Said,
JitenDa, looks like there is still a problem when you say, "In case of orbital electron, the electrostatic force is balanced by the centrifugal force (mv2/r), and there is no net force acting on the orbital electron along its tangential path."
O.K. No tangential component of the force. You already have said that.
What about radial component? Is that zero? That means no net force? Centripetal force is provided by the elctrostatic force. But who supplies the centrifugal force to beat the centripetal force? Answer is: nobody. Centrifugal force is a fictitious force. It cannot neutralize a real force. So it is the centripetal force furnished by the electrostaic force that keeps the electron busy revolving around the nucleus.
Regards.
-Subimal
Reply:
I think you still have misconceptions about orbital electron. Why don't you consult an Atomic Physics book. Let me give you a reference: Atomic Physics by E. V. SHPOL'SKII. The reason why I am asking you to consult a book is because no matter what I say, it will not convince you until you consult a book, which is fine with me. I want you to be absolutely convinced in this regard. I am going to quote a part from this book later in our discussion. By the way, some of your comments are demeaning and offensive. I am not sure if you realize that. We are discussing Physics, not personal matter. I can write demeaning comments also, but that is not my style.
As a friend, and older brother, I want to tell you that you are overconfident about your knowledge of physics. I have studied physics a lot longer than you; I am still studying, yet I am not as confident as you about my physics background. If I misquote or has misconception about something, just point it out. I will take it back. Please do not convey the impression that I am trying to deny any established fact here.
Now, lets comeback to the orbital electron. The electrostatic force is attracting the electron towards the nucleus, and the centripetal force also pulling the electron toward the nucleus. If these two forces are acting in the same direction then, tell me, why electron is still remaining in the same orbit? There is no explanation without the centrifugal force. Now, I am quoting from the book: "The absolute value of the force which retains the electron in its orbit is F = e**2/r**2. This force F is equal to the centrifugal inertial force e**2/r**2 = mrw**2, where w is the angular frequency of the electron."
The only way electron will be able to stay in the orbit if these two forces attains an equilibrium (i.e. cancels one another). If they do not cancel, meaning net force acting in the radial direction, that resultant force would have caused displacement along the radial direction. Centripetal acceleration is not a real acceleration in the sense that a real acceleration would require a change in the magnitude of the velocity. It is called the centripetal acceleration due to the fact that velocity is a vector quantity and a directional change also manifests as a change in velocity.
Another issue is that, there is no work done by the electron for its displacement from one point to another along the orbit, meaning that there is no resultant force acting on the electron at any point in its orbit. Each atomic orbit represents a stationary state with discrete energy values.
The existence of centrifugal force can be felt by passengers in a car, when car is following a curved road. It pushes passengers towards the side. Another place you can see this centrifugal force in action is when your washing machine goes through spin cycle to remove water from your clothing. Centrifugal force compresses clothes against the wall of the washing machine to rid the water off. Another example can be found when scientists determine the orbit for a satellite. The radius of the orbit or the velocity is obtained from the following condition,
Gravitational force = Centrifugal force
Forces are vector quantities, and two forces can attain an equilibrium condition only when they are equal in magnitude but act in the opposite direction. No one can explain these equilibrium conditions without the concept of the centrifugal force.
Your concept of "electrostatic force furnishes centripetal force" is wrong. Electrostatic force arises from charges only, nothing to do with the centripetal force. These two forces are independent. They are needed to attain an equilibrium condition. One does not give rise to the other automatically. They become related only when you want to attain an equilibrium. You cannot balance two forces when they are acting in the same direction, unless they are both zero. In case of the Satellite, you can find the orbit and its velocity by balancing these two forces. If satellite loses this equilibrium due to slower velocity, it has to adjust to a smaller orbit, where this equilibrium will again occur. If it loses its velocity completely, there is no centrifugal force to balance the gravitational force and it will crush on to earth. The same situation occurs in case of the orbital electron also.
Jiten Roy
------------------------------------
*****************************************
Sign the Petition : Release the Arrested University Teachers Immediately : An Appeal to the Caretaker Government of Bangladesh
http://www.mukto-mona.com/human_rights/university_teachers_arrest.htm
*****************************************
Daily Star publishes an interview with Mukto-Mona
http://www.mukto-mona.com/news/daily_star/daily_star_MM.pdf
*****************************************
MM site is blocked in Islamic countries such as UAE. Members of those theocratic states, kindly use any proxy (such as http://proxy.org/) to access mukto-mona.
*****************************************
Mukto-Mona Celebrates 5th Anniversary
http://www.mukto-mona.com/Special_Event_/5_yrs_anniv/index.htm
*****************************************
Mukto-Mona Celebrates Earth Day:
http://www.mukto-mona.com/Special_Event_/Earth_day2006/index.htm
*****************************************
Kansat Uprising : A Special Page from Mukto-Mona
http://www.mukto-mona.com/human_rights/kansat2006/members/
*****************************************
MM Project : Grand assembly of local freedom fighters at Raumari
http://www.mukto-mona.com/project/Roumari/freedom_fighters_union300306.htm
*****************************************
German Bangla Radio Interviews Mukto-Mona Members:
http://www.mukto-mona.com/Special_Event_/Darwin_day/german_radio/
Mukto-Mona Celebrates Darwin Day:
http://www.mukto-mona.com/Special_Event_/Darwin_day/index.htm
*****************************************
Some FAQ's about Mukto-Mona:
http://www.mukto-mona.com/new_site/mukto-mona/faq_mm.htm
****************************************************
VISIT MUKTO-MONA WEB-SITE : http://www.mukto-mona.com/
****************************************************
"I disapprove of what you say, but I will defend to the death your right to say it".
-Beatrice Hall [pseudonym: S.G. Tallentyre], 190Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/mukto-mona/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/mukto-mona/join
(Yahoo! ID required)
<*> To change settings via email:
mailto:mukto-mona-digest@yahoogroups.com
mailto:mukto-mona-fullfeatured@yahoogroups.com
<*> To unsubscribe from this group, send an email to:
mukto-mona-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to: