clear my concept....physxx mcq

[hassam]

i actual compared it with the case of lifting an apple in gravitatonal field....and got the ryt anser.....bt i wanted to ask if there was a negative charge...then would the work increase or decrease....and clear this to me....cos i think in dat case my analogy to earth wouldnt work

 

[Xthegreat]

what's the answer for this?

 

[hassam]

A

 

[Xthegreat]

well then, if the charge is negative then the force is to the left. and if you move it to the right, you would increase the PE by Fs.

u can look at it this way, PE is the energy stored to do work. so if the charge is further away from where it wants to go, then it would have a higher PE.

ok?

 

[Zishi]

i actual compared it with the case of lifting an apple in gravitatonal field....and got the ryt anser.....bt i wanted to ask if there was a negative charge...then would the work increase or decrease....and clear this to me....cos i think in dat case my analogy to earth wouldnt work

It's kinda very simple. Think about energy conversions. As charge is negative, and is moving in the direction of electric field, (being both repelled by -ve plate and attracted by +ve plate). Its KE decreases, and so EPE increases. Remember, total energy is always conserved.

 

[alphabravocharlie]

Aoa. Dude i still don't get it. The charge is positive and is moving in the direction of the field, from positive to negative, how is energy decreasing.