95.26: Two positive point charges repel each other with force 0.36 N when their ;.s sdn7n.ctq g5v 9bc8aajm3 separation is 1.5 m. What force do they exert on each other when thesn8v m7;n. gc3a t5scjb.da 9qir separation is 1.0 m?

  12.13 Approximately how many electrons must be removed from an elect3(o-p7cg v4s c3ktq vvrically neutqtv v7- pvg34oc(3kcs ral 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 e/)1pzwfcoz b4zw 3q5constant current of 3.20 A for a time of 3.0 hour. Which one of the following choices /wbpo5 )zfeqc13w4zzbest represents the number of electrons that pass through a vertical cross-section of the wire during this time?

  13.07: Two identical particles are fixed in place a distance of 0.50mb )il- 0hcms7bsx+wq 2apart. The electric force that one particle exerts on the other has a magnitude of 3.00 N. Which one of the following chs0s7c +l2mih wb)bxq-oices best represents the magnitude of each particle’s charge?

  07.25: If two protons are spaced by a distance R, what is the ratio of t 4y, y*us8,z pqd(-isrul cy7phe gravidyq,c-lru*zppus (y7y i ,s84tational 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 prv-ca0cq/o /cv oton of charge Q and mass M being placed near a helium 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 oq/cv 0-/v accelectric force from the other and which object experiences the greatest magnitude of acceleration? Ignore gravity.

  94.39: A small object with charg8 hea .nujpi:(e q and weight mg 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 h(.ijnue8pa: the vertical. What is the sign and magnitude of q?

  09.38: A small object of mass M and charge Q 53.bus)d nzod5 io .jnis connected to an insulating massless string in a vacuum on Earth. A uniform electric )db.n s553 i uond.zojfield exists throughout the region of the vacuum as indicated. The mass remains in static 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 a regif 1neq -i(o2 auasw0 p.yv5k-son between charged capacitor plates with equal speed v. Electron A is directed horizop1fouaa wqnsys5 v02.(ie k--ntally to the left while electron B is directed 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 point charge exerts a force ofx1dy6pr ma0ox// n5 ur 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 posi5r1 0/dxnr ya6xupmo/ tive point charge exerts on the negative point charge?

  98.08: When two charged point-like ob/8v a:9sn6ubidm ;e, gvvfos *jects are separated by a distance R, the force between them:e guv,8s fab nvd;m6/iv*so 9 is F. If the distance between them is quadrupled, the force between them is

  03.18: Two identical electrical point chax;azdb0z+n -e.2e7 c yaf4oifrges Q, separated by a distance produce an +i0f2zxabnc-df o7y . az;e4 eelectrical force ofF on one another. If the distance is decreased to a distance of 0.40, what is the strength of
the resulting force?

  96.34: A point charge +q is placed midway between two pog:/bhbr)z 1*ocysh0 x int charges +3q and -q separated by a distance 2d. If Coulomb’s constant is k, the magnitude of the forchbrsbyg:o c)x *1/zh0e on the charge +q is:

  01.31: A positive poin * nzvk,tkq1q:t charge of +q and a negative point charge of -q are separated by a distance d. What would be the magnitude of the electric field midway between the two chargq t:qnz *k1vk,es?

  08.33: Two point charges are(bu2au k6; d/oxrwiy 5 fixed on the x-axis inotherwise empty space as shown bew( 6ayduk xo2ur 5/;bilow.
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-axik91vm(w thlb8 ly01x vs in otherwise empty space as shown belt1vw1lm80 kvhbl(x9 yow.
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 –4Q are8pf ehe h eybg4+.xc8xq(s(p ( arranged as shown in the accompanying diagram. At which of the label8(fs exq8y+e(hp4gc ex.(bphed points is the field most nearly zero?

  98.30: Four positive point charges are arranged as shortyvkp;k* a ;9y7mg z3leya:6wn in the accompanying diagram. The force between charges 1 and 3 is 6.0 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 fo *rglp9;a:y;v3 6kae z7mtk yyrce on charge 3 is most nearly

  94.08: A point charge of +4.0 μC is placed on the negative x-axis 0.2fp,y u -2f rrq6brg8+s0 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 t -pb8yfur+q f2srg, r6he origin. The net electric field at the origin is zero. What is q?

  95.36: Assume the electric potential is zero at infinity. A point charmt: un 4e+5l k8z67voidm:ju jge of +4.0μC is placed on the negative x-axis 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 m to the right of the origin. The net electric potential at the origi8vt7d : jmzk mi:eun+46o5 ujln is also zero. What is q’s charge?

  03.27: Four electrical charges are arranged on the corners of a 10 cm squar15 8gklbs.cd dma 6ot4 vpnzi o+o7/;ze as shown. What would be the direction of the resulting electrdm8;dt1kz/o7. b5cg san 4 voi+p6zlo ic
field at the center point P?

  14.10: Two charges −Q and +Q, a0n h-rkm2a-gi*gl. tha3 /delre fixed in place on the x-axis, each a distance a from the origin as shown. At the point labeled P, a distance along they-axd-/3latg2 -m.al0hhnge *ikr is from the origin, what is the direction of the electric field from the given charges?

  16.33 Given the configuration of three charges, +Q, +Q;qrwx qy46lavi f: yl hm,4c);, and −2Q, which one of the following choices best represents thq4:rx6wvl lq;4hfiay,m c ; )ye direction of the electric field at the point P and the sign of the electric potential at P from these charges?

  17.43: A semi-circle has radius R, total charge Q, and a charge pej2kav00u -hw rr unit length given as 0 r huw0ak2jv-$λ=λ_0cosθ$ 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?