Electric Potential Energy A charge q in an electric field behaves similarly to a mass m in a gravitational field. The electric force F = qE is conservative. Work done Fx cos qEs cos Change in potential energy from position a to b: U U b U a qEs cos UU is independent of the path from position a to b: Electric Potential The electric field is related to how fast the potential
is changing: For a constant electric field: Electric Potential and Potential Difference Ua Va (scalar quantity) Electric Potential: q - independent of q Electric potential - depends on position a difference V between a and b:
Ub U a V Vb Va q q U E x x is along field lines q Electric Potential and Potential Energy U U b U a qVb Va Difference in potential energy
Difference in electric potential Electric potential V has units of Joules/Coulomb which is defined as a Volt: 1 Volt = 1 Joule/Coulomb One Joule is the work done in moving one Coulomb of charge through a potential difference of one Volt. Electric field has units of Newtons/Coulomb or Volts/ meter: 1N/C = 1 J/(mC) = 1 V/m Analogy between Electric and Gravitational Fields q
E m G d q m U = qV = - qEd U = - mgd The charge and mass lose potential energy and gain kinetic energy when they move in the direction of the
field. Kinetic Energy of a Charge Accelerated by an Electric Field The kinetic energy acquired by an electron or a proton accelerated through a potential difference of 1000 Volts: Uba = qVba = (1.60 x 10-19 C)(1000 V) = 1.60 x 10-13 J = 1000 eV (electron volts) = 1 keV (kilo electron volt) One electron-volt (1 eV) is the kinetic energy gained by an elemental charge (electron or proton) when it is accelerated through a potential difference of one Volt. 1 eV = 1.6 x 10-19 J
Electric Potential Energy: The Electron Volt Suppose a point charge q is moved between two points a and b in space, where the electric potentials due to other charges are Va and Vb. The change in potential energy is: UU = Ub Ua = q(Vb Va) = qVba Unit = Electron Volt (eV): 1 eV = 1.6 x 10-19 J e.g. a proton accelerated through a potential difference of 200 kV acquires a kinetic energy of 200 keV (losing 200 keV of electric potential energy).
Electric Potential due to Point Charge Electric Field: Q E k 2 (radially outward) r Using Calculus, it can be shown 1 1 V Vb Va kQ rb ra Convention: V=0 at infinite r Q
V k (electric potential) r Electric Potential due to a Point Charge Electric potential at a distance r from a positive charge Q Electric potential at a distance r from a negative charge Q Equipotential Surfaces Equipotential surfaces are surfaces of constant electric
potential (just as lines of constant elevation on a topological map are lines of constant gravitational potential). Equipotential surfaces are always perpendicular to the direction of the electric field. (just as the fall line is perpendicular to the contour lines on a topological map). Charged Parallel Plates Charges Two Equal and Opposite
CRUD-matrix Funktioners relation til entiteter kan også fastlægges i en CRUD-matrix, (Create, Retrieve/Read, Update og Delete). Create = Insert Retrieve = Select Designer, repositorie og database 12/10 2005 Beskrivelses- og analyse-teknikker understøttet af Oracle Designer Del 2 af 2: Proces...
Alan Robock is a specialist in this domain. In bold are the sections I chose for my translation text. I decided to focus on the first sections in order to keep some coherence. They include the introduction, the second part...
Tahoma Arial Wingdings Times New Roman Comic Sans MS Slit 1_Slit PowerPoint Presentation MAMMALS CLASSIFICATION CHIROPTERA Megabats Characteristics of Megabats Microbats CHARACTERISTICS OF MICROBATS OF ALL BATS IN THE WORLD: Can you differentiate between megachiroptera and microchiroptera?
(PHD VIVA) Background of the study. Ghana has a rich cultural heritage built over a long period of time, whose common values represents the people's collective national heritage (National Commission on Culture, 2004). ... PowerPoint Presentation Last modified by:
Anna is reading a 300-page book. She can read a page in two minutes. If she has finished reading 75 percent of the pages, how many minutes of reading does she have left? ... 1004 Slide 235 59. In the...
Shortcuts/Indirect Method Comments. Use these only once the student understands the basics of counting, addition, and subtraction. The student should be able to understand why the shortcut is possible and the reasoning behind it
Allusions. Brief or slight mention of someone or something to emphasize your point. Marvin Gaye there's no brother, brother. ... Provide a definition of a term for explanation, for further description , to show the essential nature, to define boundaries,...
Reptile Lungs. Respiration is no longer through the skin, but only through internally protected and moistened lungs. They have a much greater surface area for the exchange of gases. They are inflated and deflated by the expansion & contraction of...
Ready to download the document? Go ahead and hit continue!