95.26: Two positive point charges repel each other with fu z4ew *p74gvv3sc:9nteh9shorce 0.36 N when their separation is 1.5 m. What force do they exert on each otherehtzuh ws4cvns: vp943 *97 ge when their separation is 1.0 m?

  12.13 Approximately how many electrons must be removed from ad nt6d 02 x,*ptlhi5b9e.wzs(q 9iuhan electrically neutral object to give it a n( * d,5p 0 hq2duiahes96wt lz.xi9ntbet charge of Q = + 1.00 C ?

  13.15 In a circuit, the flow of electrons in a horizontal wire produces a congck56cu7g s:ystant 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-secy5u7gk :c sc6gtion of the wire during this time?

  13.07: Two identical particles are fixed in place a distance of 0.4pnyxvj w*ycj id.1,4 50mapart. The elect1d yv.x4jw ,nyjci4*pric force that one particle 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 are spaced by a distance R, what is the ratio off(t 4y8,z 8ocnzv/sew the gravitat fv8,ceonw4 (sz/z8ytional 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 mass M bret;cm xxh)p 4vh -54ieing 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 -e)5th cvix m4;xp4hrmagnitude of electric force from the other and which object experiences the greatest magnitude of acceleration? Ignore gravity.

  94.39: A small object with ffhibaa n6k +61fdx )r/jg)hzlh:j41 charge q and weight mg is attached to one end of a string of length L. The other end is attached t g6 fkf flib:z ha1/ahd+)x61)j4 hnrjo 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 chbn7:b w a6a8vlarge Q is connected 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 static equilibrium at an angle of θ with the vertical as shown in the figure. When the string is cut, which :7ba navbl 8w6of the illustrated paths best indicates the trajectory of the mass?

  13.29 Two electrons enter a rept-amj24v8r aft 73k .y rpcn)gion between charged capacitor plates with equal speed v. Electron A is directed horizontally to the left while electron B i.k)8 rn-v37frc pjmat2tapy 4s 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 of magnitude F on a negative pov h3zcldj+z 5ryf. 3o+int 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 posirv3 5hj+lz y3c+zo .dftive point charge exerts on the negative point charge?

  98.08: When two charged point+g4ptvue;6 m -wl*7vt -upytq-like objects are separated by a distance R, the force between them is F. If the distanut-q 6lu+ywmv7ev 4ptt-*g ;pce between them is quadrupled, the force between them is

  03.18: Two identical electritcbt g*/ 84qmu8h/ehbcal point charges Q, separated by a distance produce an electrical force ofF on one another. If the distance is decreased to a distance of 0.4tmghb*b /8e8q hu4/ct 0, what is the strength of
the resulting force?

  96.34: A point charge +q is placed midway between two point charges +3q azmkyz ,/zx,1j nd -q separated by a distance 2d. If Coulomb’s constant is k, thyj1z kz,,zx/ me magnitude of the force on the charge +q is:

  01.31: A positive point charge of +q and a negative point cv 8++du wfwfm4harge of -q are separated by a distance d. What would be the magnitude of the electd++ 8 mwv4ffwuric field midway between the two charges?

  08.33: Two point charges are fixed on the x-axis inotherwise empty space as showpw9n+kusa r:o)u: o9wn below.rouw au:9+kps )no9:w
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 emptyb o9uc u,)a+ b;;tsfbp space as shown bebo cb;sb9+p; utu a,f)low.
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 are arranged as shown18./zm4e-ew neadx dl in the accompanying diagram. At which of the labeled points is the fi8dwz -4 a1dm/eele n.xeld most nearly zero?

  98.30: Four positive point charges are arranged as shown in the*gw:vv wwa9/y accompanying diagram. The force between charges 1 and 3 is 6.0 N; the force between charges 2 and 3 is 5.0 N;/v:9gywv *wwa 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.k oznhy:8/p s-v(uh, j0 μC is placed on the negative x-axis 0.20 m to the left of the origin, as shown in the accompanying f-s z8hu k/v(oynp :hj,igure. 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 q?

  95.36: Assume the electric potential is zero at infinity. A point charge of +4 (t2rt 8ag-vtt 0/jrd+ejdj7y(rs e)e.0μC is placed on the negative x-axis 0.20 m to the left of the origin, as shownte- ge(j dav jr t 27d)jsr+/tr(ey80t 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 origin is also zero. What is q’s charge?

  03.27: Four electrical charges are arranged on the corne*-k0qji qm) l.m y-mptt(9m wbu6d,a krs of a 10 cm square as shown. What wouljq*wl,k 0myqukamm-(t9 i-md.) 6 btpd be the direction of the resulting electric
field at the center point P?

  14.10: Two charges −Q and +Q, are fos o6.+ 8qmmb7xed kik n:c9t1ixed in place on the x-axis, each a distance a from the 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 i8d:s1.7kmbo c 6em9+ ontqxkthe given charges?

  16.33 Given the configuration of three charges, +Q, +Q, an;.n)wz8vfh y dd −2Q, which one of the folloz. n ywh8);fvdwing 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 R4l4rrr utsb b3 .dzjvwq1)m i)r26v4q , total charge Q, and a charge per unit length given asv .tiz6r)1r42qlv 34jm ) b4uqbdrwrs $λ=λ_0cosθ$ 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?