An electric force moves a charge of +1.40 x 10^-4 C from point A to point B and performs 4.70 x 10^-3 J of work on the charge.
(a) What is the difference (EPEA - EPEB) between the electric potential energies of the charge at the two points?
____________J
(b) Determine the potential difference (VA - VB) between the two points.
____________V
(c) State which point is at the higher potential.
_____Point A
_____Point B
_____They are at the same potential.
(a) The electric potential energy decrease, (EPEA - EPEB), equals the work done by the force
(b) Divide (EPEA - EPEB) by the charge to get the electric potential difference
(c) (EPEA - EPEB) is positive, and so is VA - VB. That should tell you which is V higher.
(a) The difference in electric potential energy (EPE) between two points is equal to the work done on a charge to move it between those points. Thus, the difference (EPEA - EPEB) is equal to the work done on the charge, which is given as 4.70 x 10^-3 J. Therefore, the difference in electric potential energies is 4.70 x 10^-3 J.
(b) The potential difference (V) between two points is the difference in electric potential energies per unit charge. Therefore, the potential difference (VA - VB) can be calculated by dividing the difference in electric potential energies (which we found in part (a)) by the charge (+1.40 x 10^-4 C) that was moved between the points.
Potential difference (VA - VB) = (EPEA - EPEB) / charge
Plugging in the values, we have:
Potential difference (VA - VB) = (4.70 x 10^-3 J) / (+1.40 x 10^-4 C)
Calculating this expression will give you the potential difference in volts (V).
(c) In order to determine which point is at a higher potential, we need to compare the potential energies at points A and B. If the difference in potential energies (EPEA - EPEB) is positive, then point A is at a higher potential, while if the difference is negative, then point B is at a higher potential.