Question

If a positive charge is moved toward a negative charge, does the potential energy of the positive charge increase or decrease? Explain

Answer 1

P.E. of the system increases or decreases ? and system is a +ve and -ve charge? right...

Answer 2

Qualitatively, things 'want' to go to lower PE. Positive 'wants' to go to negative (& vise-versa), so the potential energy is decreacing.

Answer 3

thanks!

Answer 4

Also, you have to work really hard to wrench away the two entwined charges, and potential energy will readily turn into kinetic, and obviously of its own accord this isn't going to happen.

Answer 5

Although, I like to think mathematically where I can:\[-\frac{ \partial U}{\partial x}=F\] So the force is opposite in direction to the gradient (change wrt space) of the PE. See http://en.wikipedia.org/wiki/Scalar_potential

Answer 6

btw what will happen to KE?will it increase?@henpen

Answer 7

2 ways of thinking about it:
1- Yes because of energy conservation
2- Yes because a force is acting on it