The Naked Scientists

The Naked Scientists Forum

Author Topic: What are "energy" and "work" ?  (Read 28389 times)

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #75 on: 20/10/2010 03:51:59 »
Then the equation must be wrong? I agree that photons are massless, the equation only shows the energy required to produce that photon.
That equation is wrong for photons. The correct one, valid for all particles and regardless if stationary or moving (in SR) is this:

E2 = (mc2)2 + (cp)2

p = momentum.

For light, in classical EM, E = cp. If you apply it to photons (certainly you will agree on the fact this is allowed) you find:

(cp)2 = (mc2)2 + (cp)2

=> 0 = (mc2)2

so m = 0.
This is  pompous and complicated formula because you do not use correct scientific terms. ;D
 
                 E=m'c²

                            p=(m+m')* v

E - energy for any object
p - momentum for any object
m - usual mass,this mass has gravitation field
m'- activated mass(mass turned into energy),this mass has not gravitation field
c - light speed
v - speed of object
                          :P
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
What are "energy" and "work" ?
« Reply #76 on: 20/10/2010 04:15:55 »
WOAHH!!

Simplified,

Please try to be be careful with your translation (I know it's not easy) but "pompous" is probably not what you really meant to say. "Pompous" is a big insult in English.

It means "you are just saying something, but it means nothing."

 

Offline lightarrow

  • Neilep Level Member
  • ******
  • Posts: 4586
  • Thanked: 7 times
    • View Profile
What are "energy" and "work" ?
« Reply #77 on: 20/10/2010 15:44:55 »
                 E=m'c²

                            p=(m+m')* v

E - energy for any object
p - momentum for any object
m - usual mass,this mass has gravitation field
m'- activated mass(mass turned into energy),this mass has not gravitation field
c - light speed
v - speed of object
nonsense.
 

Post by simplified click to view.

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #78 on: 20/10/2010 17:30:32 »
Shrunk
                 E=m'c²

                            p=(m+m')* v

E - energy for any object
p - momentum for any object
m - usual mass,this mass has gravitation field
m'- activated mass(mass turned into energy),this mass has not gravitation field
c - light speed
v - speed of object
nonsense.
Your definition is a law for dark people.
 

Post by peppercorn click to view.

Offline peppercorn

  • Neilep Level Member
  • ******
  • Posts: 1466
    • View Profile
    • solar
What are "energy" and "work" ?
« Reply #79 on: 20/10/2010 17:52:59 »
Shrunk
Your definition is a law for dark people.
??? ??? ???

What? ...Are you saying this a law for people from the African sub-continent??? :D


[To clarify for anyone who might have misunderstood - my intention above is to gently ridicule the poster's English NOT make a racist comment.  Thanks!]
« Last Edit: 21/10/2010 15:57:58 by peppercorn »
 

Post by simplified click to view.

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #80 on: 20/10/2010 18:06:36 »
Shrunk


What? ...Are you saying this a law for people from the African sub-continent??? :D
[/quote]Can you disprove the formulae?
 

Post by peppercorn click to view.

Offline peppercorn

  • Neilep Level Member
  • ******
  • Posts: 1466
    • View Profile
    • solar
What are "energy" and "work" ?
« Reply #81 on: 20/10/2010 18:19:41 »
Shrunk
Can you disprove the formulae?

I wasn't aware that the responsibility was on me to disprove it!
 

Post by imatfaal click to view.

Offline imatfaal

  • Neilep Level Member
  • ******
  • Posts: 2787
  • rouge moderator
    • View Profile
What are "energy" and "work" ?
« Reply #82 on: 21/10/2010 13:48:49 »
Shrunk
Sorry - but is this forum now using  "for dark people" as a metaphor for bad science and ignorance.  FFS I thought there were rules about racism.  I have reported it to the moderators and I hope they do something about it. 

Matthew
 

Post by BenV click to view.

Offline BenV

  • Neilep Level Member
  • ******
  • Posts: 1503
    • View Profile
What are "energy" and "work" ?
« Reply #83 on: 21/10/2010 13:57:13 »
Shrunk
Simplified - I have sent you a private message.  Please respond to me as soon as you receive it.

In the meantime, this thread will be locked.

This thread is now unlocked to give Simplified the opportunity to clarify his meaning.
« Last Edit: 21/10/2010 16:45:53 by BenV »
 

Post by simplified click to view.

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #84 on: 21/10/2010 18:57:19 »
Shrunk
Sorry - but is this forum now using  "for dark people" as a metaphor for bad science and ignorance.  FFS I thought there were rules about racism.  I have reported it to the moderators and I hope they do something about it. 

Matthew
I never thought of a literal origin of this expression.I am so sorry.
 

Post by imatfaal click to view.

Offline imatfaal

  • Neilep Level Member
  • ******
  • Posts: 2787
  • rouge moderator
    • View Profile
What are "energy" and "work" ?
« Reply #85 on: 21/10/2010 19:36:27 »
Shrunk
We all say things in heat of an argument that we might not have fully thought out - the fact that large portions of the world suffer because of prejudice means that I tend to be over-sensitive when I come across the language of bigotry in an arena such as this great forum.  Your last post reads true and with that apology I personally hope that the forum can go back to the cut-and-thrust of academic debate and avoid disharmony .  Regards  Matthew Newell - Imatfaal

ps come to think of it the forum probably has a rule against profanity - and if the derivation of FFS isnt profane then nothing is!
 

Post by Geezer click to view.

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
What are "energy" and "work" ?
« Reply #86 on: 22/10/2010 05:58:04 »
Shrunk
"What we've got here is failure to communicate"




Perhaps, due to a translation problem, Simplified meant "people in the dark"
« Last Edit: 22/10/2010 06:00:40 by Geezer »
 

Post by simplified click to view.

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #87 on: 22/10/2010 14:42:50 »
Shrunk
"What we've got here is failure to communicate"




Perhaps, due to a translation problem, Simplified meant "people in the dark"
People without light ideas.
 

Post by lightarrow click to view.

Offline lightarrow

  • Neilep Level Member
  • ******
  • Posts: 4586
  • Thanked: 7 times
    • View Profile
What are "energy" and "work" ?
« Reply #88 on: 22/10/2010 17:41:05 »
Shrunk
"What we've got here is failure to communicate"




Perhaps, due to a translation problem, Simplified meant "people in the dark"
People without light ideas.
Then is appropriate for those people who write "smoky", "unclear", non-scientific things, with the aim to make other believe they are scientific.
« Last Edit: 23/10/2010 13:10:42 by lightarrow »
 

Offline BenV

  • Neilep Level Member
  • ******
  • Posts: 1503
    • View Profile
What are "energy" and "work" ?
« Reply #89 on: 22/10/2010 17:59:37 »
The off topic/misunderstanding posts are shrunk to allow easier reading of the actual science discussion - hopefully folks can pick it up from here...
 

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #90 on: 23/10/2010 04:28:14 »
If  activated mass does not exist, then communication of object with the past exists. It slows down time of object. [8D]
 

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #91 on: 23/10/2010 04:34:34 »
Energy is communication of object with the past .
 

Offline Bill S

  • Neilep Level Member
  • ******
  • Posts: 1830
  • Thanked: 12 times
    • View Profile
What are "energy" and "work" ?
« Reply #92 on: 27/10/2010 18:15:40 »
Quote from: simplified
Energy is communication of object with the past

Please explain, or change your name from "simplified", it doesn't suit you. :P 
 

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #93 on: 30/10/2010 17:26:55 »
Then the equation must be wrong? I agree that photons are massless, the equation only shows the energy required to produce that photon.
That equation is wrong for photons. The correct one, valid for all particles and regardless if stationary or moving (in SR) is this:

E2 = (mc2)2 + (cp)2

p = momentum.

For light, in classical EM, E = cp. If you apply it to photons (certainly you will agree on the fact this is allowed) you find:

(cp)2 = (mc2)2 + (cp)2

=> 0 = (mc2)2

so m = 0.
Well. But which units I should use in this formula?
 

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #94 on: 30/10/2010 17:38:45 »
Units of measurement
 

Offline lightarrow

  • Neilep Level Member
  • ******
  • Posts: 4586
  • Thanked: 7 times
    • View Profile
What are "energy" and "work" ?
« Reply #95 on: 30/10/2010 22:56:31 »
Then the equation must be wrong? I agree that photons are massless, the equation only shows the energy required to produce that photon.
That equation is wrong for photons. The correct one, valid for all particles and regardless if stationary or moving (in SR) is this:

E2 = (mc2)2 + (cp)2

p = momentum.

For light, in classical EM, E = cp. If you apply it to photons (certainly you will agree on the fact this is allowed) you find:

(cp)2 = (mc2)2 + (cp)2

=> 0 = (mc2)2

so m = 0.
Well. But which units I should use in this formula?
It's a strange question. The measurement's units are:
kg for mass,
Joule for energy,
m*s-1 for c 
kg*m*s-1 for p.
Joule = N*m = kg*m2*s-2
 

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #96 on: 31/10/2010 05:14:04 »
Object travels with speed of 1 m/s.Mass of the object=1kg
I want to calculate energy of this object.
   E ≈ mv²/2 = 0,5 J
Let's use your formula:
                        E² = (mc²)² + (cp)²

E²=(1*299792458²)²+(299792458*1*1)²=8,077608713*10³³

   E=√(8,077608713*10³³)=89875517873681764,5 J  :o

I don't understand where is my mistake? :(
 
 

Offline Geezer

  • Neilep Level Member
  • ******
  • Posts: 8328
  • "Vive la résistance!"
    • View Profile
What are "energy" and "work" ?
« Reply #97 on: 31/10/2010 05:52:15 »
I'm not sure how to explain this properly, but please try to remember that English may not be first language of some of our posters. Translation can be a tricky business, so please try to make sure there are no misunderstandings because of a translation problem.

Thanks!
 

Offline lightarrow

  • Neilep Level Member
  • ******
  • Posts: 4586
  • Thanked: 7 times
    • View Profile
What are "energy" and "work" ?
« Reply #98 on: 31/10/2010 10:23:19 »
Object travels with speed of 1 m/s.Mass of the object=1kg
I want to calculate energy of this object.
   E ≈ mv²/2 = 0,5 J
Wrong. What you have written is *not* the energy E. With the term "energy" in relativity and in particle physics, we intend "total energy". What you have written is *just* kinetic energy. E = kinetic energy + mc2 (in absence of a potential or other kinds of energy).
(Let's say is a language problem, as Geezer said... :))
« Last Edit: 31/10/2010 10:27:47 by lightarrow »
 

Offline simplified

  • Sr. Member
  • ****
  • Posts: 428
    • View Profile
What are "energy" and "work" ?
« Reply #99 on: 31/10/2010 15:25:10 »
Object travels with speed of 1 m/s.Mass of the object=1kg
I want to calculate energy of this object.
   E ≈ mv²/2 = 0,5 J
Wrong. What you have written is *not* the energy E. With the term "energy" in relativity and in particle physics, we intend "total energy". What you have written is *just* kinetic energy. E = kinetic energy + mc2 (in absence of a potential or other kinds of energy).
(Let's say is a language problem, as Geezer said... :))
Thank you very much.
 

The Naked Scientists Forum

What are "energy" and "work" ?
« Reply #99 on: 31/10/2010 15:25:10 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums