Potential energy charge physics homework

1. Jan 23, 2010

aloshi

http://www.pluggakuten.se/wiki/images/b/be/111.JPG [Broken]

the picture shows that one posetiv report goes from p_1 to p_2. it will get a potential energy, this work that man has stored down on that few report to that place where it befinna, is bigger the more potential energy has it. this means that that potential energy is the work that the object can perform out because of its position.

1) how can it move from p_1 to p_2? it must be something as do that it goes against the direction that it want to, otherwise did not have it any performed work of course?

2) how comes it that accelerar compare with an identical charge,that we let the charge leave from the centers of the the homogeneous electrical field strength?

Last edited by a moderator: May 4, 2017
2. Jan 23, 2010

tiny-tim

Hi aloshi!
Yes, you're right, the positive charge cannot go towards the positive plate unless a force acts on it. The force is not shown in the diagram.

And the force times the distance (d) tells you the amount of work done , and that equals the difference in potential energy.

I honestly can't tell what you're asking in 2).

Last edited by a moderator: May 4, 2017
3. Jan 24, 2010

aloshi

Re: charge

1)
why is tension, (voltage), in an electrical field or in a circuit not it same? which factors are tension dependence of? how can one influence
2)
in a circuit so is not tension, voltage, it same, why is it so? it complete voltage is counted for the whole circuit, why is it so?

4. Jan 24, 2010

tiny-tim

Hi aloshi!

(btw, we don't call it "tension" except sometimes in the case of "high-tension transmission", of kilovolts … in all other cases, we say "voltage" )

The definitions of voltage look different, but they are the same …

they are both energy/charge !!

(a volt is a joule per coulomb: 1V = 1J/C)

In an electric field, E, the voltage is:​

energy/charge

= work/charge

= force"dot"distance/charge

= (from the Lorentz force) electric field"dot"distance, or dV = E.dr

In an current, I (with power P), the voltage is:​

energy/charge

= (energy/time)/(charge/time)

= power/current, or V = P/I.