Problem 1FTD: Conceptual Example 20.1 shows that the gravitational force between an electron and a proton is about... Problem 2FTD: A free neutron is unstable and soon decays to other particles, one of them a proton. Must there be... Problem 3FTD: Where in Fig. 20.5 could you put a third charge so it would experience no net force? Would it be in... Problem 4FTD: Why should the test charge used to measure an electric field be small? Problem 5FTD: Equation 20.3 gives the electric field of a point charge. Does the direction of (a) r or (b) E... Problem 6FTD: Is the electric force on a charged particle always in the direction of the field? Explain. Problem 7FTD: Why does a dipole, which has no net charge, produce an electric field? Problem 8FTD: The ring in Example 20.6 carries total charge Q, and the point P is the same distance r=x2+a2 from... Problem 9FTD: A spherical balloon is initially uncharged. If you spread positive charge uniformly over the... Problem 10FTD: Under what circumstances is the path of a charged particle a parabola? A circle? Problem 11FTD: Why should there be a force between two dipoles, which each have zero net charge? Problem 12FTD: Dipoles A and B are both located in the field of a point charge Q, as shown in Fig. 20.27. Does... Problem 13E: Suppose the electron and proton charges differed by one part in one billion. Estimate the net charge... Problem 14E: A typical lightning flash delivers about 25 C of negative charge from cloud to ground. How many... Problem 15E: Protons and neutrons are made from combinations of the two most common quarks, the u quark (charge )... Problem 16E: Earth carries a net charge of about 5 105 C. How many more electrons are there than protons on... Problem 17E: As they fly, honeybees may acquire electric charges of about 180 pC. Electric forces between charged... Problem 18E: The electron and proton in a hydrogen atom are 52.9 pm apart. Find the magnitude of the electric... Problem 19E: An electron at Earths surface experiences a gravitational force meg. How far away can a proton be... Problem 20E: You break a piece of Styrofoam packing material, and it releases lots of little spheres whose... Problem 21E: A charge q is at the point x = 1 m, y = 0 m. Write expressions for the unit vectors you would use in... Problem 22E: A proton is at the origin and an electron is at the point x = 0.41 nm, y = 0.36 nm. Find the... Problem 23E: An electron experiences an electric force of 0.61 nN. Whats the field strength at its location? Problem 24E: Find the magnitude of the electric force on a 2.0-C charge in a 100-N/C electric field. Problem 25E: A 68-nC charge experiences a 150-mN force in a certain electric field. Find (a) the field strength... Problem 26E: The electric field inside a cell membrane is 8.0 MN/C. Whats the force on a singly charged ion in... Problem 27E: A 1.0-C charge experiences a 10-N electric force in a certain electric field. What force would a... Problem 28E: The electron in a hydrogen atom is 52.9 pm from the proton. At this distance, whats the strength of... Problem 29E: In Fig. 20.28, point P is midway between the two charges. Find the electric field in the plane of... Problem 30E: The water molecules dipole moment is 6.2 1030Cm. What would be the separation distance if the... Problem 31E: The electric field 22 cm from a long wire carrying a uniform line charge density is 1.9 kN/C. Whats... Problem 32E: Find the line charge density on a long wire if the electric field 45 cm from the wire has magnitude... Problem 33E: Find the magnitude of the electric field due to a charged ring of radius a and total charge Q on the... Problem 34E: In his famous 1909 experiment that demonstrated quantization of electric charge, R. A. Millikan... Problem 35E: How strong an electric field is needed to accelerate electrons in an X-ray tube from rest to... Problem 36E: A proton moving to the right at 3.8l05m/s enters a region where a 56-kN/C electric field points to... Problem 37E: An electrostatic analyzer like that of Example 20.8 has b = 7.5 cm. What value of E0 will enable the... Problem 38P: A 2-g ping-pong ball rubbed against a wool jacket acquires a net positive charge of 1C. Estimate the... Problem 39P: Two charges, one whose magnitude is twice as large as the others, are located 12.5 cm apart and... Problem 40P: A proton is on the x-axis at x = 1.6 nm. An electron is on the y-axis at y = 0.85 nm. Find the net... Problem 41P: A 9.5C charge is at x = 15cm, y = 5.0cm and a 3.2-C charge is at x = 4.4 cm, y = 11 cm. Find the... Problem 42P: A charge 3q is at the origin, and a charge 2q is on the positive x-axis at x = a. Where would you... Problem 43P: A negative charge q lies midway between two positive charges +Q. What must Q be such that the... Problem 44P: In Fig. 20.29, take q1 = 68 C, q2 = 34 C, and q3 = 15 C. Find the electric force on q3. FIGURE... Problem 45P: FIGURE 20.20 Problems 44 and 45 In Fig. 20.29, take q1 = 25 C and q2 = 20 C. If the force on q1... Problem 46P: DNA fragments introduced into an electrophoresis apparatus (see Application, page 360) generally... Problem 47P: A 65-C point charge is at the origin. Find the electric field at the points (a) x = 50 cm, y = 0 cm;... Problem 48P: A 1.0-C charge and a 2.0-C charge are 10 cm apart. Find a point where the electric field is zero. Problem 49P: A proton is at the origin and an ion is at x = 5.0 nm. If the electric field is zero at x = 5.0nm,... Problem 50P: (a) Find an expression for the electric field on the y-axis due to the two charges q in Fig. 20.7.... Problem 51P: A dipole lies on the y-axis and consists of an electron at y = 0.60 nm and a proton at y = 0.60 nm.... Problem 52P: Show that the field on the x-axis for the dipole of Example 20.5 is given by Equation 20.6b, for |x|... Problem 53P: Youre 1.44 m from a charge distribution that is well under 1 cm in size. You measure an electric... Problem 54P: Three identical charges q form an equilateral triangle of side a, with two charges on the x-axis and... Problem 55P: Two identical small metal spheres initially carry charges q1 and q2. When theyre 1.0 m apart, they... Problem 56P: Two 38.0-C charges are attached to opposite ends of a spring with spring constant k = 145 N/m and... Problem 57P: A thin rod lies on the x-axis between x = 0 and x = L and carries total charge Q distributed... Problem 58P: An electron is moving in a circular path around a long, uniformly charged wire carrying 2.5 nC/m.... Problem 59P: Find the line charge density on a long wire if a 6.8-g particle carrying 2.1 nC describes a circular... Problem 60P: A dipole with dipole moment 1.5 nCm is oriented at 30 to a 4.0-MN/C electric field. Find (a) the... Problem 61P: You have a job examining patent applications. Youre presented with the device in Fig. 20.30, which... Problem 62P: A 5.0-m strand of DNA carries charge +e per nm of length. Treating it as a charged line, whats the... Problem 63P: A molecule has its dipole moment aligned with a 1.2-kN/C electric field. If it takes 3.1 1027J to... Problem 64P: Two identical dipoles, each of charge q and separation a, are a distance x apart, as shown in Fig.... Problem 65P: A dipole with charges q and separation 2a is located a distance x from a point charge +Q, oriented... Problem 66P: An electron is at the origin, and an ion with charge +5e is at x = 10 nm. Find a point where the... Problem 67P: Youre taking physical chemistry, and your professor is discussing molecular dipole moments. Water,... Problem 68P: The electric field on the axis of a uniformly charged ring has magnitude 380 kN/C at a point 5.0 cm... Problem 69P: An electric quadrupole consists of two oppositely directed dipoles in close proximity, (a) Calculate... Problem 70P: You measure the electric field on a dipoles axis, at a distance from the dipole thats large compared... Problem 71P: A straight wire 10 m long carries 25 C distributed uniformly over its length, (a) Whats the line... Problem 72P: Figure 20.34 shows a thin rod of length L carrying charge Q distributed uniformly over its length,... Problem 73P: Figure 20.35 shows a thin, uniformly charged disk of radius R. Imagine the disk divided into rings... Problem 74P: Use the result of Problem 73 to show that the field of an infinite, uniformly charged flat sheet is... Problem 75P: Use the binomial theorem to show that, for x R, the result of Problem 73 reduces to the field of a... Problem 76P: A semicircular loop of radius a carries positive charge Q distributed uniformly. Find the electric... Problem 77P: In Example 20.2, find the position on the y-axis where Q will experience the greatest force. Problem 78P: A thin rod carries charge Q distributed uniformly over its length L and is situated on the x-axis... Problem 79P: A thin rod extends along the x-axis from x = 0 to x = L and carries line charge density = 0(x/L)2,... Problem 80P: A rod of length 2L lies on the x-axis, centered at the origin, and carries line charge density =... Problem 81P: Youre working on the design of an ink-jet printer. Ink drops of mass m, speed v, and charge q will... Problem 82PP: BIO The human heart consists largely of elongated muscle cells, some 100m long and 15 m in diameter.... Problem 83PP: At a given distance, far from the heart compared with its size, the electric field a. is weaker... Problem 84PP: The difference between Figs. 20.38a and 20.38b that results in an external electric field in one... Problem 85PP: At the instant shown in Fig. 20.38c, theres an electric field within the heart that points... format_list_bulleted