95.26: Two positive point charges repel each other with force 0.3k7ntx v)8s w,p6 N when their separation is 1.5 m. What force do thesk np)7wx vt8,y exert on each other when their separation is 1.0 m?

  12.13 Approximately how many electrons must be removed from an electrically neu8; hpjbk sf,a+;q q5putral object to give it a net char uq sa;h pf+;,8qbjkp5ge of Q = + 1.00 C ?

  13.15 In a circuit, the flow of electrons .h.n6bom w9pp in 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 hnb..69mow ppthe 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 0.5y);i n; i7xeu/inivp:f2 pfk :0mapart. The electric force that one particle exertsi:x v;; )fn72neip i/ykfpi:u 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* pl l4luy3 mx0:s1nxs R, what is the ratio of the gravitational force that one1xymxu *llps0l :n4s3
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 anzy byhe br26ciw st5/f*17 l1yd mass M being plac*hy5b7 yls1 ezbw/ ft2c6y1r ied 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 magnitude of acceleration? Ignore gravity.

  94.39: A small object wi.rnjt 3bp r3m1.nf,nc we eg0,th charge q and weight mg is attached to one end of a string of length L. The other endgtp.j,w3 e n.nrf,nerc30 bm1 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 l ov,)lh4pgu2 Q is connected to an insulating massless string in a vacuum on Earth. A uniform electric field exists throughout the region24l lgo u,pvh) 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 capacitor platv6q5:8 xuux) 6 pvzvr5oxqc .+ug4wazr9l4ises with equal speed v. Electron A is directed horizontally to th vvu:cxp.rur 855+u i w )6s4xzqagx qvol649ze 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 exer2luz2 vlrkg a758q7m its 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 p k2ag8vm2l7 zrqlui7 5oint charge?

  98.08: When two charged point-like objects are separated cszmlf 04z3 igjh2s61 by a distance R, the force between them is F. If the distance between them is quadrupled, the force between them i64ji0hm z12 g3sc zlsfs

  03.18: Two identical electrical point charges Q, separated bjv o,/dojxe 03y a distance produce an electrical force ofF on one another. If the distance is decreased to a distance of 0.40, what io,jv0 j dxo3e/s the strength of
the resulting force?

  96.34: A point charge +q is placed midway between two point-kev emup1x 7;q4ctsrn .0+we charges +3q and -q separated by a distance 2d. If Coulomb’s constant is k, thexqmv ;n w .pt-sc01kr4 7e+eue magnitude of the force on the charge +q is:

  01.31: A positive point charge of +q atbqa p/jr8fp7u+o6i:j kv7 k/ nd a negative point charge of -q are separated by a distance d. What woul obaqtukjfk:7pij8 v+ /r67p /d be the magnitude of the electric field midway between the two charges?

  08.33: Two point charges are fixed on the x-axis r8a o zgc7)lpki lij8e.(cz2:inotherwise empty space as shown bj8cz lae)loi zrp8g27(cik: . elow.
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 arut8 tu545ldk me fixed on the x-axis in otherwise empty space as shou5d kl845tmutwn 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 +Q and –4Q are arranged apm x6 de7x(4bws shown in the accompanying diagram. At which of the labeled points is the field most near(x4 mpd7e6 wbxly zero?

  98.30: Four positive point ch:9b m9wfaqsj z 4aet;wca- .-marges are arranged as shown 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 wf.mq9azs 4j-;wct9e-b m:aaand 4 is 3.0 N. The magnitude of the total force on charge 3 is most nearly

  94.08: A point charge of +4:8 9o 0 ;ix7.xpqecy l5cargpu)pk4 zo.0 μC 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 mto th).a;icxe84 0: yp9 uzlx7q 5ropocgkpe right of the origin. The net electric field at the origin is zero. What is q?

  95.36: Assume the electric potent0m8 *ov1j djifial is zero at infinity. A point charge of +4.0μC is placed *f8v1jdo ji0m 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 origin is also zero. What is q’s charge?

  03.27: Four electrical charges are arranged on thxbma .uf*/0 tt5ldnjf7x.n- ae corners of a 10 cm square as shown. What wouutj. 7tx n/a-0dmf* fn.5balx ld be the direction of the resulting electric
field at the center point P?

  14.10: Two charges −Q and +Q, are fixed in pck/b dt,g:4kqq5 r*l4y r1aogxhc0 m/lace on the x-axis, each a distance a from the origin as shown. At the point labeled P, a distance along they-axcxlg, a4h/ 0b*kqq :c rrkgd15t4/myois from the origin, what is the direction of the electric field from the given charges?

  16.33 Given the configuratioi-e2b/ (vg-y;wispqtg g/, i lh flf-.n of three charges, +Q, +Q, and −2Q, which one of the following choic(li b2i/w /fg,i-g .fqy -sghl -;vetpes 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 R, total pc/l3vn9jqp0 ksdht* 99 2r ydp6 fd0rcharge Q, and a charge per unit length t 9rd9j*pn9s k dv2frh3/pqy00d6lpc given 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?