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Misc => Physics Questions => Topic started by: leeyiren on September 29, 2010, 04:01:47 am



Title: Charge and Energy
Post by: leeyiren on September 29, 2010, 04:01:47 am
Can someone define the differences and relationship between charge and energy? Both have the symbol Q and charge is measured in coulomb while energy is measured in joules. What else?


Title: Re: Charge and Energy
Post by: lookang on September 29, 2010, 07:54:20 am
u can explore this applet
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1918.0
i just added 29Sept2010
6 added KE = 0.5*m*v^2 ;  PE = q*Vnet;  TE = KE+PE; due to question by leeyiren http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1965.new#new

in the context of a charge in a potential V
Charge = q
Potential Energy = q*V where V could be = (1/4*pi*elipson)Q/r
Kinetic energy = + 0.5*m*v^2
Electric charge is a physical property of matter which causes it to experience a force when near other electrically charged matter. http://www.answers.com/topic/electric-charge
energy is a quantity that is often understood as the ability to perform work. http://en.wikipedia.org/wiki/Energy

the analogue of your question is what is the difference between mass and energy
The inertial mass of an object determines its acceleration in the presence of an applied force http://en.wikipedia.org/wiki/Mass
energy is a quantity that is often understood as the ability to perform work. http://en.wikipedia.org/wiki/Energy

does it help to see the parallelism of the concept to mass?


Title: Re: Charge and Energy
Post by: leeyiren on September 29, 2010, 03:44:27 pm
Is 1C positive or negative?

PS: See the thread about F=ma and reply yes or no? thx


Title: Re: Charge and Energy
Post by: lookang on September 29, 2010, 03:59:25 pm
Is 1C positive or negative?
1C = +1C, so it is positive


Title: Re: Charge and Energy
Post by: leeyiren on September 29, 2010, 04:06:33 pm
you mean there is such thing as -1C? but I thought coulomb is like kg, no -ve.


Title: Re: Charge and Energy
Post by: lookang on September 29, 2010, 04:27:56 pm
you mean there is such thing as -1C? but I thought coulomb is like kg, no -ve.
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1918.0
yes.
charge has + and - types.
electrons is negatively charges


we have no evidence of the existence of negative mass in the real life but in quantum physics world, things the size of atoms, there is something called anti-mass. but that is another story ;)