95.26: Two positive point charges repel each othty .c/ns1nh,s er with force 0.36 N when their sepa/n hcs ys.1,ntration is 1.5 m. What force do they exert on each other when their separation is 1.0 m?

  12.13 Approximately how many electrons must be removed fromn1y - e2xfe(nh an electrically neutral object to give it a net charge of Q = + 1.00e1 fhn(2x-ney C ?

  13.15 In a circuit, the flow of electrons int ocpdtg .,l pjw27c/2 a horizontal wire produces a constant 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 tgc 27t/ p,wdct jol2p.hrough a vertical cross-section of the wire during this time?

  13.07: Two identical particles are fixed in place a distance of 0.w) p 6s4vi+nl+li;rve50mapart. The electric force that one part)vs+6p;w 4rvlinle +i icle exerts on the other has a magnitude of 3.00 N. Which one of the following choices best represents the magnitude of each particle’s charge?

  07.25: If two protons areit ryf0*:1gt2vqy zr x54g by8 spaced by a distance R, what is the ratio of the gravitational force that o148xrrygv* qzf bgyt t5:yi 20ne
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 mass M p; hdci ;cnrg8wv ,* x8pqek.p6r0s :mbeing placed near a helium nucleuc.dcw*;r ; xe8p prm86q,k:hp0 isgnvs (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 mgic rew5wlb 2:ct;7p u; is attached to one end of a string of length L. The othe wcp7t;;2:irl c 5bwuer 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 of q?

  09.38: A small object of mass M and charge Q is connected to a qsa/xsc sx61 gz2r3w g))umy1n insulating massless string in a vacuum on Earth. A uniform electric fieldsxua2 cq) wrxs3)/z6m1 1sggy 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 region between charged capacitorsctr x (7k92hmo sbu4fib/ e;uxt/3j/ plates with equal speed v. Electron A is directed horizontally to the left while electron B is dih//u3om9fs4(7srjek ut2/cti xb ; bx rected 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 ch9+ (b lzb o4r2yk c*dqhl65l dotvc/o3arge 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 tl t29d*yovho ro 6qkz54/(lbcd+b3lche positive point charge exerts on the negative point charge?

  98.08: When two charged point-like objects ar)iqrp o38mke0 e separated by a distance R, the force between them is F. If the distance between them is quad0)keqo i3 rmp8rupled, the force between them is

  03.18: Two identical electrical point charges Q, separi + ytdog0 6:,qi/vbi 6ga9brjated by a distance produce an electrical force ofF on one: yi9j giotb+ 0 dravq6b6i/,g 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 point ch:4i*d zhl6ah, j, rdqxyr i21harges +3q and -q separated by a distance 2d. If Coulomb’s constant is k, the magnitude of the force on the zhi21aidl,*yd :q,rh6jrxh 4 charge +q is:

  01.31: A positive point charge o,ns(5x ql- k v-x)e5fo8r tvnjf +q and a negative point charge of -q are separated by a distance d. What would be the magnit5kn-n,8 t -)sve o( 5jrvxqxflude of the electric field midway between the two charges?

  08.33: Two point chargep*u ktp+5h dhqrtj:,g;:nnt5: m jy .js are fixed on the x-axis inotherwise empty space as shown belontqrj5t ;m dj n j :htpk.::*,y+5uhgpw.
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 , /ea *uayqxf9k 23ovqg6aj/ v *ys8pvthe x-axis in otherwise empty space as sho3v6 /x9py q akyv/aefa *q,sg2 vj*o8uwn below.
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 + x k/vx;3cthwt,jd(2o Q and –4Q are arranged as shown in the accompanying diagram. At which of the labeled points is the field most xdxkt2 /;t 3(ovjhw, cnearly zero?

  98.30: Four positive point charges are ad1f-x- dp 5j.lwe9ersrranged as shown in the accompanying diagram. The force between c e5lwf1jrde-9- d.xs pharges 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 force on charge 3 is most nearly

  94.08: A point charge of +4.0 μC iots ag** a hz;uz.(0axs 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 **;otz.(s0g uazaxh aon the positive x-axis 0.30 mto the right of the 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 charge of +4x+3t11py nqyy ts4+n x.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 thex 1x+yn4s+y31qnytp t origin. The net electric potential at the origin is also zero. What is q’s charge?

  03.27: Four electrical charges are arranged on the corner7r21hcrs wr ;ys of a 10 cm square as shown. What would be the directioy72;rhwr sc1rn of the resulting electric
field at the center point P?

  14.10: Two charges −Q and +Q, are fixed in plac grt1(x*r csjjg*7(eme on the x-axis, each a distance a from the origin as shown. At the point labeled P, a jmje(cs7 gt*( x1rr*gdistance along they-axis from the origin, what is the direction of the electric field from the given charges?

  16.33 Given the configura0l g*vp.f+5eg b :.cek;hkt wjtion of three charges, +Q, +Q, and −2Q, which one of thpwchkvf+ t. jek0 5 .;le*g:bge following choices best represents the 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 q o)xzp7m8/si R, total charge Q, and a charge per unit length given s8x /7p)zimqo 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?