Question
question 23
ratio of (b) Find gil laal. the charges? surfaces Section 194 Electric Field Their Relation to the Two equipotential surfaces surround a How far is the 190-V surface from the 7 32. An equipotential surface that surro otential of 490 an area of 1.1 m of a point charge q. Location B lies ssm The inner and outer sur 20, Location A is 3,00 m to the negative and a positive charge the same line and is 4.00 450 v. What are the difference between the two locations is Va charges, a potential difference of ab mbrane. The thickness of the cell me magnitude and sign of the charge? 21. Identical +1.8 charge are fixed to adjacent corners of a magnitude of the electric field in the What charge (magnitude and algebraic sign) should be to one of the the point charge (q fixed empty corners, so that the total electric potential at the remaining empty 34. A positive surface A. which has corner is 0 V? by an equipotential +4.5 x 10-11 C) distance test charge (qo and H 2g ae fixed in place, wi surface B, which has a rad te drawn through the negative equipotential from surface A to surface on the dashed 2.00 m between them. A dasi charge, perpendicular ssm A spark plug in an at a distance L from mei conductors that are separated by a where the total potential is cri F i electric spark jumps between them, th 13. ssm Determine the electric poten- .s oouc 10T Vin. What is the mag tial energy for the array of three AV between the conductors? charges in the drawing relative to its 36. The drawing that accompanies Pr value when the charges are infinitely equipotential surfaces in cross section far away and infinitely far apart Determine the magnitude and directio 24. Two identical point charges Specify whether the electric field poi 7.20 x 10- Cry are fixed at the drawing diagonally opposite corners of a +20.0 uc square with sides of length 0.480 m, -15.0 uc s 37. ssm mmh An electric field has A test charge (ga 2.40 x 10 C). Problem 23 and is directed downward. The field is mass of 6.60 x 10- at a point P within this region is 155 released from rest at one of the empty corners of the square. Determine (a) 6.0 the speed of the test charge when it reaches the center of the square. below P. (c) 8,0 x 10-3 m directl e 25, mmh Two protons are moving directly toward one another. When fro they are very far apart, their initial speeds are 3.00 x 106 m/s. what is "38. e An electron is released rest at the negative plate of a paral the distance of closest approach? plate capacitor and accelerates to
Explanation / Answer
The potential energy of the base pair,
PE1 = kq1q2/d = -9*10^9*15*20*10^-12/4=-0.675 J
The potential energy of the vertical pair,
PE2 = kq1q2/r = -9*10^9*15*8*10^-12/3 = -0.36 J
The potential energy of the charges on hypotenuses,
PE3 = kq1q2/r = 9*10^9*8*20*10^-12/5 = 0.288 J
So the net potential energy PE = 0.288-0.36-0.675 = -0.747 J.
