Concept explainers
BIO Electric field in body cell The electric potential difference across the membrane of a body cell is
(higher on the outside than on the inside). The cell membrane is
Want to see the full answer?
Check out a sample textbook solutionChapter 18 Solutions
College Physics
Additional Science Textbook Solutions
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
College Physics
Essential University Physics: Volume 1 (3rd Edition)
Physics for Scientists and Engineers with Modern Physics
University Physics Volume 2
Introduction to Electrodynamics
- To form a helium atom, an alpha particle that contains two protons and two neutrons is fixed at one location, and two electrons are brought in from far away, one at a time. The first electron is placed at 0.6001010 m from the alpha particle and held there while the second electron is brought to 0.6001010 m from the alpha particle on the other side from the first electron. See die final configuration below, (a) How much work is done in each step? (b) What is the electrostatic energy of die alpha particle and two electrons in the final configuration?arrow_forwardProblems 72, 73, and 74 are grouped. 72. A Figure P26.72 shows a source consisting of two identical parallel disks of radius R. The x axis runs through the center of each disk. Each disk carries an excess charge uniformly distributed on its surface. The disk on the left has a total positive charge Q, and the disk on the right has a total negative charge Q. The distance between the disks is 3R, and point A is 2R from the positively charged disk. Find an expression for the electric potential at point A between the disks on the x axis. Approximate any square roots to three significant figures. FIGURE P26.72 Problems 72, 73, and 74.arrow_forwardA simple and common technique for accelerating electrons is shown in Figure 18.55, where there is a uniform electric field between two plates. Electrons are released, usually from a hot filament, near the negative plate, and there is a small hole in the positive plate that allows the electrons to continue moving. (a) Calculate the acceleration of the electorn if the field strength is 2.50104 N/C. (b) Explain why the electron will not be pulled back to the positive plate once it moves through the hole.arrow_forward
- Review. Two insulating spheres have radii 0.300 cm and 0.500 cm, masses 0.100 kg and 0.700 kg, and uniformly distributed charges 2.00 C and 3.00 C. They are released from rest when their centers are separated by 1.00 m. (a) How fast will each be moving when they collide? (b) What If? It the spheres were conductors, would the speeds be greater or less than those calculated in part (a)? Explain.arrow_forwardIntegrated Concepts An electron has an initial velocity of 5.00106m/s in a uniform 2.00105N/C strength electric field. the field accelerates the electron in the direction opposite to its initial velocity. (a) What is the direction of the electric field? (b) How far does the electron travel before coming to rest? (c) How long does it take the electron to come to rest? (d) What is the electron’s velocity when it returns to its starting point?arrow_forwardEarth has a net charge that produces an electric field of approximately 150 N/C downward at its surface. (a) What is the magnitude and sign of the excess charge, noting the electric field of a conducting sphere is equivalent to a point charge at its center? (b) What acceleration will the field produce on a free electron near Earth’s surface? (c) What mass object with a single extra electron will have its weight supported by this field?arrow_forward
- (a) Would life be different if the electron were positively charged and the proton were negatively charged? (b) Does the choice of signs have any bearing on physical and chemical interactions? Explain your answers.arrow_forward(a) What is the direction and magnitude of an electric field that supports the weight of a free election near the surface of Earth? (b) Discuss what the small value for this field implies regarding the relative strength of the gravitational and electrostatic forces.arrow_forwardA proton and an alpha particle (charge = 2e, mass = 6.64 1027 kg) are initially at rest, separated by 4.00 1015 m. (a) If they are both released simultaneously, explain why you cant find their velocities at infinity using only conservation of energy. (b) What other conservation law can be applied in this case? (c) Find the speeds of the proton and alpha particle, respectively, at infinity.arrow_forward
- Calculate the initial (from rest) acceleration of a proton in a 5.00X106 N/C electric field (such as created by a research Van de Graaff). ). Explicitly show how you follow the steps in the Problem-Solving Strategy for electrostatics.arrow_forwardA hydrogen atom consists of an electron and a proton. Model the hydrogen atom as a dipole with separation d = 1010 m. a. Estimate the electric potential energy of the hydrogen atom. b. How much work does an external force do in liberating the electron from the atom? c. If the external force does more than the work you found in part (b), what can you say about the electrons motion when it is very far from the proton?arrow_forward(a) What is the direction of the total Coulomb force on q in Figure 18.46 if q is negative, qa= qcand both are negative, and qb= qcand both are positive? (b) What is the direction of the electric field at the center of the square in this situation?arrow_forward
- College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax CollegePrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning