95.26: Two positive p :tajkfysp+t4s2jelo ;y6 p (*oint charges repel each other with force 0.36 N when their separation is 1.5 m. What force do they lyo tsty:kj2eja4;s6+*fp(p exert on each other when their separation is 1.0 m?

  12.13 Approximately how many electrons must be removed from an eltci4jt omvy:5yp9 *t*ectrically neutral object to give it a net cha *y v:y*ot pttc54mji9rge of Q = + 1.00 C ?

  13.15 In a circuit, the flow of electrons in a hori/uqz* 0-4xzl iw q1jgli0r+5czn7 vxqzontal wire produces a constant0+uji z/qx inqzl17xrwc -4z* 5lgv 0q 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 this time?

  13.07: Two identical particles are fixed in)5 9kzkj2i/mrh f ov(hlobi 73 place a distance of 0.50mapart. The electric force that one particle ehb(k7)f5iovzr/3h kmj9 il o2xerts 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 of the graviu nce(bafl sa,61; :altational force that o fc6n:,eaa;1 bllus(a ne
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 expe/f0cdk m/1m/pdrg 9noriment with a proton 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 electric force from the other and which object experiences the greatest gm/ crk0/9mn1p d /ofdmagnitude of acceleration? Ignore gravity.

  94.39: A small object with charge q and weight mg is attached to one end of a s;no r: z6m(a*;ky1acth lr( yqtring of length L. The other end is attached to a stationary support. The system is placed in a uniform horizqr*c(1yyzarh n;ak6 l(ot:; montal 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 e/b1q;n6w)dbv*wa 8yk8ob2sy; hjcx 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 yb q2 a6v1bx;cjsed8;)hnyw8wob */kshown 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 betwm,krjch5(d3(wg*:i 7p 2g supw *aex been charged capacitor plates with equal speed v. Electron A is directed horiz:js gk(dmbc3w,7w5 (ipreu 2**xhg pa ontally 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 charg t; ri: ljg- fcp3w.872fkbzywe 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 that3;2- t:yjpfck.zr ibl w7f8wg the positive point charge exerts on the negative point charge?

  98.08: When two charged point-like objects are separated by a distance v)vp7 1txrypl h( ,5onR, the force between them is F. If the distance between them is quadrupled, the force bvp1l nx,vt yo(h r5)7petween them is

  03.18: Two identical electrical point charges Q, separated b rdilq271m;btv r-i5 by a distance produce an electrical fob v1m idb57r;2itr ql-rce 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 point c(xjl.epzk:mo7 vuwst,( /(cz harges +3q and -q sepxl.( zm(p,:u7vzk /eswc(otj arated by a distance 2d. If Coulomb’s constant is k, the magnitude of the force on the charge +q is:

  01.31: A positive pointb xjxa:);2i rn charge of +q and a negative point charge of -q are separated by a distance d. What woux n 2xabj;i)r:ld be the magnitude of the electric field midway between the two charges?

  08.33: Two point char/x9t+ bmceq n;ges are fixed on the x-axis inotherwise empty space as shown b+xe9;tc /mq bnelow.
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 rmk1,ayier +6x-axis in otherwise empty space as shown belyri 6mk1 ,aer+ow.
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 shown in the accompanying diaglnbnd43dip9 ;4:nebtram. At which of the labeled points is the fpdd b9:t4nlni3n; b4e ield most nearly zero?

  98.30: Four positive point charges are arranged as shown in the accompanyqby4nlf6) i+s ing diagram. The force between charges 1 and 3 is 6.0 N; the forc f4lbs)yq6 +nie 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 dbo+3u *z,c arplaced 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 mto the right o,+cz d a3bour*f 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 f19e v5w//s u4vrs onjof +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 srf/vnvuews59/1s jo4 econd 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 onoh 9s9w wubz fejlvev5 :)28)c the corners of a 10 cm square as shown. What would be the di8: obu v)2zfscewl)99 jhve5wrection of the resulting electric
field at the center point P?

  14.10: Two charges −Q and +Q, are fixeullnz hmr*(.. d in place on the x-axis, each a distance a from the origin as shown. At the point labeled P, a distance along they-axi.u(.l*mhrznl s 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, and −2Q, which one ot .go 82micfy(f the following choices best represents the directig cto(f8.2myi on 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 f,/ 0eugyii n,uonq9+ charge Q, and a charge per unit length gi 0+,u9go fi/nqui ,yenven 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?