95.26: Two positive poihvatg3:uq;h4: ke igx-+ ;:akp vmlu1nt charges repel each other with force 0.36 N when their separation is 1.5 m. What force do they exert on each other when their separation is 1.0 p3va::u1;xg-m 4;ke:+khavq ug lhti m?

  12.13 Approximately how many electrons mu 0h l0l7zut0tsst be removed from an electrically neutral0 ll07tu s0tzh object to give it a net charge of Q = + 1.00 C ?

  13.15 In a circuit, the flow of electrons in a horizontal wire produces a c)b 8toi +oem/5 v:valx2 pewg.onstant current of 3.20 A for a time of 3.0 hour. Which one of the following choices best represents the number of electrons that pass through a vertical cross-section of the wire during t m/o5lx+obe8awe .pvv)2:g ithis time?

  13.07: Two identical particles are fixed in place a distanenh*7wx 5;( d6 1q+eccpbugzusfgc44h p0 qg /ce of 0.50mapart. The electric force that one particle exerts on the other has a magnitude of 3.00 N. Which one of the cfx* wpp;b5eq0cudg7zs1 eh hgcq( 4un 46g+/following choices best represents the magnitude of each particle’s charge?

  07.25: If two protons are spaced(t :f2f6y pbsrxc+ y1i by a distance R, what is the ratio of the gravitationabf2rfpcy :ytx1+ ( 6isl force that one
proton exerts on the other to the electric force that one proton exerts on the other?That is,$\frac{F_{gravity}}{F_{electric}}$=

  10.12: A scientist sets up an experiment with a proton of charge Q and massugxxpqr0haf3n;1j2+ M being placed near a helium un;r jgf1x+hax3q02p nucleus (2 protons and 2 neutrons) of charge +2Q and mass 4M. The objects are each released from rest and begin to move. From the scientist’s point of view, which choice best describes the object that experiences the greatest magnitude of electric force from the other and which object experiences the greatest magnitude of acceleration? Ignore gravity.

  94.39: A small object with charge q and weight mg 9.es9wwo2k ss is attached to one end of a string of length L. The other end is attached to a stationary support. The system is placed in a uniform horizontal electric field E, as shown in the accompanying figure. In the presence of the field, the string makes a constant angle q with the vertical. What is the sign and magnitude o9.2w9wos ksesf q?

  09.38: A small object of mass M and charge Q is connesctdxa0uf v 4+;5k a/rb4yk6dcted to an insulating massless string in a vacuum on Earth. A uniform electric field exists throughout the region of the vacuum as indicated. The mass remains in 4 u ft v5s0d/aadxky+;4bc6rkstatic equilibrium at an angle of θ with the vertical as shown in the figure. When the string is cut, which of the illustrated paths best indicates the trajectory of the mass?

  13.29 Two electrons enter n8uft23, kxtxa region between charged capacitor plates with equal speed v. Electron A is directed horizontally to the left while electron B is directed utxkf,2tx 8n3 at$30^{\circ}$below the horizontal. Each electron makes it to the left-hand plate. Which one of the following choices best compares the speeds of the charges ( $V_A$, $V_B$) upon arrival at the left plate? Consider only the electrons A and B’s interactions with the constant electric field between the plates, ignoring any relativistic effects.

  08.06: A positive po(m k,at5pg o2ezp:wp s*i:bgb9-+ exkint charge exerts a force of magnitude F on a negative point charge placed a distance x away. If the distance between the two point charges is halved, what is the magnitude of the new force that the positive point charge exerts on the negative poiwegkgkm :o2 (: psab*e,zp+-95x pti bnt charge?

  98.08: When two charged point-like objects are separatedhbwuu-3)lex) by a distance R, the force between them is F. If the distance between them is quhleu-)w )bux3 adrupled, the force between them is

  03.18: Two identical electrical point charges Q, separated by a distance pr0f*,v9 eiwn n:a2 5nrygcxw.y3 win7i oduce an electrical force ofF on one another. If the distance is decreased to a distaewnrwi5 xa9 n7n iv0cfn.i2:3* wgyy ,nce of 0.40, what is the strength of
the resulting force?

  96.34: A point charge +q is placed midway between two poik0-,eh.p/x emzo, x iint charges +3q and -q separated by a distance 2d. If Coulomb’s constant oi k.,i,/zm0hxex- epis k, the magnitude of the force on the charge +q is:

  01.31: A positive point charge of +q,6s jrj/ ae9ya and a negative point charge of -q are separated by a distance d. What would be the magnitude of thej eas9,jr/y 6a electric field midway between the two charges?

  08.33: Two point charges are fixed on the x-axis inotherymr62b cdm5w+ k+,sh omp; g4iwise empty space as shown belbi4m2gmy p+,okdmw 5c;shr+ 6ow.
In which Region(s) is there a place on the x-axis (aside from infinity) at which the electric potential is equal to zero?

  08.34: Two point charges are fixed on the x-axis in otherwise empty space as shouv( dui5 km-b; 0)kupo 4 cfvbu4:u)yvwn below omy4pucv4) d)u vf :-vuub;k05kib(u.
In which Region(s) is there a place on the x-axis (aside from infinity) at which the electric field is equal to zero?

  98.23: Two charges +Q and ;3dmt-ommt qdig dpr54o0b7*–4Q are arranged as shown in the accompanying diagram. At whi mr5im-gqodt7*3o tdd0;4p bmch of the labeled points is the field most nearly zero?

  98.30: Four positive point charges (aax-.q)kpb w are arranged as shown in the accompanying diagram. The force between charges 1 and 3 is -) waqk( xpb.a6.0 N; the force between charges 2 and 3 is 5.0 N; and the force between charges 3 and 4 is 3.0 N. The magnitude of the total force on charge 3 is most nearly

  94.08: A point charge of +4.0 μC is placed on the negative x-ax,ndhgc0esx1 k ,a+hl-6 rot4 *ufn3rcis 0.20 m to the left of the origin, as shown in the accompanying figure. A second point charge q is placed on the positive x-axis 0.30 mto the right of the origin. The net electric field at the origin is zero. What is qlak3-1fgr4hc c ,+ xrhnut0e,dso6* n?

  95.36: Assume the electric potential is+ig /e8*hll g ,l )o:k+ojp r;lie-yjj zero at infinity. A point charge of +4.0μC is placed on the negative x-axis 0.20 m to the left of the origin, as shown in the accompane rhp8ykl+;, )jgloiej /g-il+*j o:lying figure. A second point charge q is placed on the positive x-axis 0.30 m to the right of the origin. The net electric potential at the origin is also zero. What is q’s charge?

  03.27: Four electrical cha wkp/8 ,)o q9o,8bbvjyzoqjj-rges are arranged on the corners of a 10 cm square as shown. What would be the direction o ,9zy/)j,kojoqq- j vb8p 8bwof the resulting electric
field at the center point P?

  14.10: Two charges −Q and +Q, are fixed in place on the x-axis,ve rc173cr ve0 each a distance a from thecrce17 0r 3vve origin as shown. At the point labeled P, a distance along they-axis from the origin, what is the direction of the electric field from the given charges?

  16.33 Given the configuration of three charges, +Qzi2.lemasb6 /ix)m * up1pm+ 4t-impx, +Q, and −2Q, which one of the following choices best represents the direction of the electric fiem)m61 ixpba mlxp4izi-/t s+.m peu2* ld at the point P and the sign of the electric potential at P from these charges?

  17.43: A semi-circle has radiusoo2tzs )jr dtw8;5dn j d:n* ,ys,w*is R, total charge Q, and a charge per unit length givtr5o) iwyn*szj,t:wnss8;2j d*d d,oen as $λ=λ_0cosθ$ with θ defined in the figure and $λ_0$ a positive constant. Which one of the following choices gives the electric field strength at the point labeled P?