College Physics: A Strategic Approach (3rd Edition)
3rd Edition
ISBN: 9780321879721
Author: Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher: PEARSON
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Textbook Question
Chapter 21, Problem 3CQ
Why is the potential energy of two opposite charges a negative number? (Note: Saying that the formula gives a negative number is not an explanation.)
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Chapter 21 Solutions
College Physics: A Strategic Approach (3rd Edition)
Ch. 21 - By moving a 10 nC charge from point A to point B,...Ch. 21 - Charge q is fired through a small hole in the...Ch. 21 - Why is the potential energy of two opposite...Ch. 21 - An electron (q = e) completes half of a circular...Ch. 21 - An electron moves along the trajectory from i to f...Ch. 21 - The graph in Figure Q21.61Q shows the electric...Ch. 21 - As shown in Figure Q21.7, two protons are launched...Ch. 21 - Each part of Figure Q21.8 shows one or more point...Ch. 21 - Figure Q21.9 shows two points inside a capacitor....Ch. 21 - A capacitor with plates separated by distanced is...
Ch. 21 - Rank in order, from most positive to most...Ch. 21 - Figure Q21.12 shows two points near a positive...Ch. 21 - A. Suppose that E = 0, throughout some region of...Ch. 21 - Rank in order, from largest to smallest, the...Ch. 21 - Figure Q21.16 shows an electric field diagram....Ch. 21 - Figure Q21.17 shows a negatively charged...Ch. 21 - Rank in order, from largest to smallest, the...Ch. 21 - A parallel-plate capacitor with plate separation d...Ch. 21 - A proton is launched from point 1 in Figure Q21...Ch. 21 - A 1.0 nC positive point charge is located at point...Ch. 21 - A 100 V battery is connected across the plates of...Ch. 21 - The electric potential is 300 V at x = 0 cm, is...Ch. 21 - What is the potential at point c? A. 400 v B. 350...Ch. 21 - At which point, a, b, or c, is the magnitude of...Ch. 21 - What is the approximate magnitude of the electric...Ch. 21 - The direction of the electric field at point b is...Ch. 21 - A +10 nC charge is moved from point c to point a....Ch. 21 - A bug zapper consists of two metal plates...Ch. 21 - An atom of helium and one of argon are singly...Ch. 21 - The dipole moment of the heart is shown at a...Ch. 21 - Moving a charge from point A, where the potential...Ch. 21 - The graph in Figure P21.2 shows the electric...Ch. 21 - It takes 3.0 J of work to move a 15 nC charge from...Ch. 21 - A 20 nC charge is moved from a point where V = 150...Ch. 21 - At one point in space, the electric potential...Ch. 21 - An electron has been accelerated from rest through...Ch. 21 - A proton has been accelerated from rest through a...Ch. 21 - What potential difference is needed to accelerate...Ch. 21 - An electron with an initial speed of 500,000 m/s...Ch. 21 - A proton with an initial speed of 800,000 m/s is...Ch. 21 - The electric potential at a point that is halfway...Ch. 21 - A 2.0 cm 2.0 cm parallel-plate capacitor has a...Ch. 21 - Two 2.00 cm 2.00 cm plates that form a...Ch. 21 - A. In Figure P21.14, which capacitor plate, left...Ch. 21 - A +25 nC charge is at the origin. How much farther...Ch. 21 - A. What is the electric potential at points A, B,...Ch. 21 - A 1.0-cm-diameter sphere is charged to a potential...Ch. 21 - What is the electric potential at the point...Ch. 21 - a. What is the potential difference between the...Ch. 21 - A. In Figure P21.20, which point, A or B, has a...Ch. 21 - In Figure P21.21, the electric potential at point...Ch. 21 - What is the potential difference between xi = 10...Ch. 21 - What are the magnitude and direction of the...Ch. 21 - What are the magnitude and direction of the...Ch. 21 - Two 2.0 cm 2.0 cm square aluminum electrodes,...Ch. 21 - An uncharged capacitor is connected to the...Ch. 21 - You need to construct a 100 pF capacitor for a...Ch. 21 - A switch that connects a battery to a 10 F...Ch. 21 - What is the voltage of a battery that will charge...Ch. 21 - Two electrodes connected to a 9.0 V battery are...Ch. 21 - Initially, the switch in Figure P21 .33 is open...Ch. 21 - A 1.2 nF parallel-plate capacitor has an air gap...Ch. 21 - A science-fair radio uses a homemade capacitor...Ch. 21 - A 25 pF parallel-plate capacitor with an air gap...Ch. 21 - Two 2.0-cm-diameter electrodes with a 0.1...Ch. 21 - A parallel-plate capacitor is connected to a...Ch. 21 - A parallel-plate capacitor is charged by a 12.0 V...Ch. 21 - To what potential should you charge a 1.0 F...Ch. 21 - A pair of 10 F capacitors in a high-power laser...Ch. 21 - Capacitor 2 has half the capacitance and twice the...Ch. 21 - Two uncharged metal spheres, spaced 15.0 cm apart,...Ch. 21 - 50 pJ of energy is stored in a 2.0 cm 2.0 cm 2.0...Ch. 21 - A 2.0-cm-diameter parallel-plate capacitor with a...Ch. 21 - What is the change in electric potential energy of...Ch. 21 - What is the potential difference V34 in Figure...Ch. 21 - A 50 nC charged particle is in a uniform electric...Ch. 21 - At a distance r from a point charge, the electric...Ch. 21 - The 4000 V equipotential surface is 10.0 cm...Ch. 21 - What is the electric potential energy of the...Ch. 21 - Two point charges 2.0 cm apart have an electric...Ch. 21 - Two positive point charges are 5.0 cm apart. If...Ch. 21 - A +3.0 nC charge is at x = 0 cm and a 1.0 nC...Ch. 21 - A 3.0 nC charge is on the x-axis at x = 9 cm and a...Ch. 21 - A 10.0 nC point charge and a +20.0 nC point charge...Ch. 21 - A 2.0-mm-diameter glass bead is positively...Ch. 21 - In a semiclassical model of the hydrogen atom, the...Ch. 21 - What is the electric potential at the point...Ch. 21 - a. What is the electric potential at point A in...Ch. 21 - A protons speed as it passes point A is 50,000...Ch. 21 - A proton follows the path shown in Figure P21.63....Ch. 21 - Electric outlets have a voltage of approximately...Ch. 21 - Estimate the magnitude of the electric field in a...Ch. 21 - A Na+ion moves from inside a cell, where the...Ch. 21 - Suppose that a molecular ion with charge 10e is...Ch. 21 - The electric field strength is 50,000 V/m inside a...Ch. 21 - A parallel-plate capacitor is charged to 5000 V. A...Ch. 21 - A proton is released from rest at the positive...Ch. 21 - The electric field strength is 20,000 V/m inside a...Ch. 21 - In the early 1900s, Robert Millikan used small...Ch. 21 - Two 2.0-cm-diameter disks spaced 2.0 mm apart form...Ch. 21 - In proton-beam therapy, a high-energy beam of...Ch. 21 - A 2.5-mm-diameter sphere is charged to 4.5 nC. An...Ch. 21 - A proton is fired from far away toward the nucleus...Ch. 21 - Two 10.0-cm-diameter electrodes 0.50 cm apart form...Ch. 21 - Two 10.0-cm-diameter electrodes 0.50 cm apart form...Ch. 21 - Determine the magnitude and direction of the...Ch. 21 - Figure P21.81 shows the electric potential on a...Ch. 21 - A capacitor consists of two 6.0-cm-diameter...Ch. 21 - The dielectric in a capacitor serves two purposes....Ch. 21 - The highest magnetic fields in the world are...Ch. 21 - The flash unit in a camera uses a special circuit...Ch. 21 - A Lightning Strike Storm clouds build up large...Ch. 21 - A Lightning Strike Storm clouds build up large...Ch. 21 - A Lightning Strike Storm clouds build up large...Ch. 21 - A Lightning Strike Storm clouds build up large...Ch. 21 - A Lightning Strike Storm clouds build up large...
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