1) The document summarizes a lecture on electrostatics that covered charge, methods of charging objects through friction and contact, instruments to measure charge like electroscopes, the quantization and conservation of charge, Coulomb's law, and the principle of superposition.
2) Various demos were listed including using teflon, glass, wood, and silk to charge objects and show their properties, as well as electroscopes, charged spheres, and generators.
3) Key concepts covered included what charge is, the atomic model of charge, quantization of charge to the elementary unit, Coulomb's inverse square law formula, and how the principle of superposition allows calculating net forces on charges.
Physics 08-Electric Forces and Electric Fields (2019).pptxjeyakumargopalan1
Electric potential (or potential) is defined as the electric potential energy per unit charge. The electric potential difference between two points is equal to the change in electric potential energy divided by the charge and is a measure of the work required to move a charge between the two points. Within a conductor, electric fields and potential differences cannot exist due to the movement of free charges. Conductors are used to shield electric fields and potential differences in applications like Faraday cages and coaxial cables.
1. Coulomb's law describes the electrostatic force of attraction or repulsion between two point charges. The magnitude of the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
2. The superposition principle states that when multiple charges exert forces on a single charge, the net electrostatic force is calculated by vector addition of the individual forces.
3. In problems involving multiple charges, the individual forces must be resolved into x and y components and then combined vectorially to find the net force and direction.
1. Coulomb's law describes the electrostatic force of attraction or repulsion between two point charges. The magnitude of the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
2. The superposition principle states that when multiple charges exert forces on a single charge, the net electrostatic force is calculated by vector addition of the individual forces.
3. In problems involving multiple charges, the individual forces are first calculated using Coulomb's law and then summed vectorially to find the net force on the charge of interest. The direction of the net force can also be determined.
This document provides an overview of a 14-day course on electrical fundamentals. It outlines the daily schedule, which covers topics in modules 3-5 over the 14 days. It includes revision sessions and tests. The daily schedule runs from 9am-1:30pm, with breaks at 10:15-10:30am and 12-12:45pm. Mornings are spent on new material and afternoons on revision and questions. Recommended resources for experimentation and circuit simulation are also provided.
The document discusses the atomic structure and models of the atom. It begins with an acknowledgement and table of contents. It then covers Dalton's atomic theory, subatomic particles like electrons and protons, cathode rays and the discovery of electrons. It discusses the charge to mass ratio of electrons, the discovery of protons and neutrons, and models of the atom including Thomson's model and Rutherford's nuclear model. It also addresses isotopes, limitations of models, wave nature of radiation, and the electromagnetic spectrum.
Structure of Atoms some basic concepts of atomic structure its history of modelling and also the present and accepted model including the quantum model of atomic structure.
The document describes J.J. Thomson's 1897 experiment to determine the specific charge (e/m ratio) of electrons using a cathode ray tube. Thomson observed that cathode rays were deflected by electric and magnetic fields, allowing him to calculate e/m. He developed a formula relating the electric and magnetic fields to electron beam deflection. His finding that e/m was constant supported the then-novel idea that cathode rays consisted of fundamental particles, which he named "corpuscles" but are now called electrons. This experiment provided early evidence challenging the belief that atoms were indivisible.
1. Electricity is the flow of electrons through a conductor. It is measured as an electric current in Amperes.
2. An electric field is the region surrounding an electric charge where other charges will experience a force. Electric field lines extend from positive charges and terminate at negative charges.
3. Examples of electric fields can be seen through the behavior of flames in an electric field and the spreading of hair charged by a Van de Graaf generator.
Physics 08-Electric Forces and Electric Fields (2019).pptxjeyakumargopalan1
Electric potential (or potential) is defined as the electric potential energy per unit charge. The electric potential difference between two points is equal to the change in electric potential energy divided by the charge and is a measure of the work required to move a charge between the two points. Within a conductor, electric fields and potential differences cannot exist due to the movement of free charges. Conductors are used to shield electric fields and potential differences in applications like Faraday cages and coaxial cables.
1. Coulomb's law describes the electrostatic force of attraction or repulsion between two point charges. The magnitude of the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
2. The superposition principle states that when multiple charges exert forces on a single charge, the net electrostatic force is calculated by vector addition of the individual forces.
3. In problems involving multiple charges, the individual forces must be resolved into x and y components and then combined vectorially to find the net force and direction.
1. Coulomb's law describes the electrostatic force of attraction or repulsion between two point charges. The magnitude of the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
2. The superposition principle states that when multiple charges exert forces on a single charge, the net electrostatic force is calculated by vector addition of the individual forces.
3. In problems involving multiple charges, the individual forces are first calculated using Coulomb's law and then summed vectorially to find the net force on the charge of interest. The direction of the net force can also be determined.
This document provides an overview of a 14-day course on electrical fundamentals. It outlines the daily schedule, which covers topics in modules 3-5 over the 14 days. It includes revision sessions and tests. The daily schedule runs from 9am-1:30pm, with breaks at 10:15-10:30am and 12-12:45pm. Mornings are spent on new material and afternoons on revision and questions. Recommended resources for experimentation and circuit simulation are also provided.
The document discusses the atomic structure and models of the atom. It begins with an acknowledgement and table of contents. It then covers Dalton's atomic theory, subatomic particles like electrons and protons, cathode rays and the discovery of electrons. It discusses the charge to mass ratio of electrons, the discovery of protons and neutrons, and models of the atom including Thomson's model and Rutherford's nuclear model. It also addresses isotopes, limitations of models, wave nature of radiation, and the electromagnetic spectrum.
Structure of Atoms some basic concepts of atomic structure its history of modelling and also the present and accepted model including the quantum model of atomic structure.
The document describes J.J. Thomson's 1897 experiment to determine the specific charge (e/m ratio) of electrons using a cathode ray tube. Thomson observed that cathode rays were deflected by electric and magnetic fields, allowing him to calculate e/m. He developed a formula relating the electric and magnetic fields to electron beam deflection. His finding that e/m was constant supported the then-novel idea that cathode rays consisted of fundamental particles, which he named "corpuscles" but are now called electrons. This experiment provided early evidence challenging the belief that atoms were indivisible.
1. Electricity is the flow of electrons through a conductor. It is measured as an electric current in Amperes.
2. An electric field is the region surrounding an electric charge where other charges will experience a force. Electric field lines extend from positive charges and terminate at negative charges.
3. Examples of electric fields can be seen through the behavior of flames in an electric field and the spreading of hair charged by a Van de Graaf generator.
1. Atoms are the basic building blocks of matter and consist of a small, dense nucleus surrounded by electrons.
2. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense nucleus containing positively charged protons and uncharged neutrons.
3. Niels Bohr proposed his model of the atom in 1913 where electrons orbit the nucleus in fixed shells at specific energy levels, explaining atomic spectra. However, it did not explain more complex atomic structures.
1. Atoms are the basic building blocks of matter and consist of a small, dense nucleus surrounded by electrons.
2. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense nucleus containing positively charged protons and uncharged neutrons.
3. Niels Bohr proposed his model of the atom in 1913 where electrons orbit the nucleus in fixed shells at specific energy levels, explaining atomic spectra. However, it did not explain more complex atomic structures.
1. Atoms are the basic building blocks of matter and consist of a small, dense nucleus surrounded by electrons.
2. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense nucleus containing positively charged protons and uncharged neutrons.
3. Niels Bohr proposed his model of the atom in 1913 in which electrons orbit the nucleus in fixed shells at specific energy levels, explaining atomic spectra.
This document discusses band theory and its application to understanding the properties of materials. It begins by introducing classical and quantum free electron theories, which treat electrons in solids as free particles. The behavior of electrons in periodic potentials is then described, leading to the development of band theory. Band theory explains that the discrete energy levels of isolated atoms merge into continuous energy bands as atoms form solids. This allows classification of materials as conductors, semiconductors, or insulators based on whether their energy bands are fully filled, partially filled, or fully empty. Band formation in silicon is provided as an example. The document concludes that band theory determines a material's ability to conduct electricity based on its energy band structure.
The document discusses atomic structure and bonding. It describes the structure of atoms including protons, neutrons, and electrons. It explains how atomic number determines the element and how isotopes have the same number of protons but different neutrons. Electron configuration and quantum numbers are also summarized. The three main types of bonds - ionic, covalent, and metallic - are introduced along with how they influence material properties.
This document summarizes key topics from a lecture on electric fields:
1) It defines electric field as the force per unit charge and discusses how electric field lines represent the behavior and strength of electric fields graphically.
2) Examples are given for calculating the electric field from point charges and continuous charge distributions using Coulomb's Law and integration.
3) Applications of electric fields including motion of charges in fields and electric dipoles are discussed. Various demonstrations are also listed.
This document summarizes a physics lecture on electrical charges and Coulomb's law. It discusses the structure of atoms and how they can become charged by gaining or losing electrons. Coulomb's law is then introduced, stating that the electrostatic force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Several example problems are worked through applying Coulomb's law to calculate the electrostatic force between charged objects at varying distances.
Electric fields arise from electric charges and can be represented by electric field lines. A positive test charge experiences a force when placed in an electric field, allowing the field strength to be calculated. The field is strongest closest to the charged object and decreases with distance. Materials are classified as conductors, insulators or semiconductors based on how easily their electrons can move. Coulomb's law defines the force between two point charges as directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Introduction
Discovery of Sub-atomic Particles
Atomic Models
Developments leading to Bohr’s Model of atom
Bohr’s Model for Hydrogen atom
Quantum Mechanical Model of the atoms
This document presents several research-inspired problems in electricity and magnetism that are suitable for introductory and intermediate-level courses. It discusses problems related to interactions between electron spins in a layered material, measurements using a SQUID magnetometer, and magnetic fields produced by superconducting magnets. Solutions to the problems are also provided.
This document provides an overview of Module 1 of General Physics 2 for Quarter 3. It includes the development team for the module and the key learning competencies, which cover describing charging by rubbing and induction, explaining electron transfer in charging by rubbing, and calculating electric force and field using Coulomb's law. The document then provides introductions to the basic concepts of electrostatics, including how bodies get charged through rubbing or induction. It also explains Coulomb's law and how to calculate electric force and field. Sample problems are provided as examples. Later sections discuss related topics like electric flux and Gauss's law, with more sample problems. A set of activities for students is also included.
1. The document discusses the subatomic particles that make up atoms, including electrons, protons, and neutrons. It defines related terms like atomic number and mass number.
2. Atoms can form isotopes that have the same number of protons but different numbers of neutrons. The forces that hold atoms together are electric forces between the positively charged protons and negatively charged electrons.
3. Oppositely charged particles attract, while similarly charged particles repel, according to the rules of electric force. This balance of forces is what allows atoms to form without collapsing in on themselves or flying apart.
Electrical Charges and Coulomb's Law.pptxReymartSupleo
1) The document discusses electrical charges and Coulomb's law. It defines electric charge, the two types of charges (positive and negative), and how like charges repel and unlike charges attract based on Coulomb's law.
2) Coulomb's law gives the formula for the magnitude of the electrostatic force between two point charges, defining it as directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
3) Several examples show how to calculate the electrostatic force between charges using Coulomb's law and solving for unknown distances or forces.
Electrostatics covers the properties of electric charges, electrostatic force, and electric fields. Key points include:
- There are two types of electric charges: positive and negative. Like charges repel and unlike charges attract.
- Charge is quantized and conserved. It exists in integer multiples of the fundamental unit, e.
- Coulomb's law describes the electrostatic force between two point charges. The force is proportional to the product of the charges and inversely proportional to the square of the distance between them.
- Electric fields are vector fields that exist around charged objects. The electric field strength is defined as the force per unit charge. Field lines are used to represent electric fields graphically.
This document provides an overview of a physics unit on semiconductors and superconductivity. It includes 20 slides on semiconductors covering topics like intrinsic and extrinsic semiconductors, doping, carrier concentrations, and the Hall effect. It also includes 37 slides on superconductivity covering critical temperature, Meissner effect, types of superconductors, flux quantization, Cooper pairs, and applications of the Josephson effect and superconductors in areas like energy transmission and magnetic levitation.
The document is an introduction to periodicity for A-level chemistry students. It discusses the organization of the periodic table by atomic number into rows and columns. It also summarizes trends in various atomic properties across period 3, including atomic radius decreasing due to nuclear charge, ionization energy generally increasing due to nuclear charge but with exceptions, electrical conductivity decreasing for nonmetals with no delocalized electrons, electronegativity increasing with nuclear charge, and melting point generally increasing for metals due to metallic bonding but decreasing for nonmetals due to weaker van der Waals forces.
E-M Effects and Atomic Physics Y11 Physics Rotation 1 2023-24.pptxKristieCorpus
The document provides an overview of magnetism and electromagnetism, describing the properties of magnets including magnetic materials, poles, attraction and repulsion of poles, and how electromagnets work using coils of wire and electric current. It also discusses magnetic fields and how they can be observed using iron filings or small compasses, as well as different types of magnets such as bar magnets and horseshoe magnets.
The document discusses several key concepts in electromagnetism including electric charge, Coulomb's law, and the superposition principle. It provides examples of how to calculate the electric force between two charges using Coulomb's law and how to find the net force on a charge from multiple other charges using the superposition principle. It also gives an example problem of using Newton's laws and electric forces to calculate the charge needed to balance the gravitational force on a hanging charged ball.
introduction,advantage and disadvantage of solar energy,Generation of solar cell: 1st 2nd 3rd generation solar cell , I-V characteristics, working,application, efficiency data and advantage solar cell.
The document discusses the atomic theory of matter and the development of atomic structure models. It describes John Dalton's atomic theory which stated that elements are composed of atoms that are unique and atoms are neither created nor destroyed in chemical reactions. The discovery of the electron by J.J. Thompson and experiments by Robert Millikan and Ernest Rutherford helped develop the modern atomic structure model of a small, dense nucleus surrounded by electrons. The document also discusses isotopes, atomic numbers, mass numbers, and how the periodic table is arranged based on atomic structure.
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
1. Atoms are the basic building blocks of matter and consist of a small, dense nucleus surrounded by electrons.
2. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense nucleus containing positively charged protons and uncharged neutrons.
3. Niels Bohr proposed his model of the atom in 1913 where electrons orbit the nucleus in fixed shells at specific energy levels, explaining atomic spectra. However, it did not explain more complex atomic structures.
1. Atoms are the basic building blocks of matter and consist of a small, dense nucleus surrounded by electrons.
2. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense nucleus containing positively charged protons and uncharged neutrons.
3. Niels Bohr proposed his model of the atom in 1913 where electrons orbit the nucleus in fixed shells at specific energy levels, explaining atomic spectra. However, it did not explain more complex atomic structures.
1. Atoms are the basic building blocks of matter and consist of a small, dense nucleus surrounded by electrons.
2. Rutherford's gold foil experiment in 1911 showed that the atom has a small, dense nucleus containing positively charged protons and uncharged neutrons.
3. Niels Bohr proposed his model of the atom in 1913 in which electrons orbit the nucleus in fixed shells at specific energy levels, explaining atomic spectra.
This document discusses band theory and its application to understanding the properties of materials. It begins by introducing classical and quantum free electron theories, which treat electrons in solids as free particles. The behavior of electrons in periodic potentials is then described, leading to the development of band theory. Band theory explains that the discrete energy levels of isolated atoms merge into continuous energy bands as atoms form solids. This allows classification of materials as conductors, semiconductors, or insulators based on whether their energy bands are fully filled, partially filled, or fully empty. Band formation in silicon is provided as an example. The document concludes that band theory determines a material's ability to conduct electricity based on its energy band structure.
The document discusses atomic structure and bonding. It describes the structure of atoms including protons, neutrons, and electrons. It explains how atomic number determines the element and how isotopes have the same number of protons but different neutrons. Electron configuration and quantum numbers are also summarized. The three main types of bonds - ionic, covalent, and metallic - are introduced along with how they influence material properties.
This document summarizes key topics from a lecture on electric fields:
1) It defines electric field as the force per unit charge and discusses how electric field lines represent the behavior and strength of electric fields graphically.
2) Examples are given for calculating the electric field from point charges and continuous charge distributions using Coulomb's Law and integration.
3) Applications of electric fields including motion of charges in fields and electric dipoles are discussed. Various demonstrations are also listed.
This document summarizes a physics lecture on electrical charges and Coulomb's law. It discusses the structure of atoms and how they can become charged by gaining or losing electrons. Coulomb's law is then introduced, stating that the electrostatic force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Several example problems are worked through applying Coulomb's law to calculate the electrostatic force between charged objects at varying distances.
Electric fields arise from electric charges and can be represented by electric field lines. A positive test charge experiences a force when placed in an electric field, allowing the field strength to be calculated. The field is strongest closest to the charged object and decreases with distance. Materials are classified as conductors, insulators or semiconductors based on how easily their electrons can move. Coulomb's law defines the force between two point charges as directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Introduction
Discovery of Sub-atomic Particles
Atomic Models
Developments leading to Bohr’s Model of atom
Bohr’s Model for Hydrogen atom
Quantum Mechanical Model of the atoms
This document presents several research-inspired problems in electricity and magnetism that are suitable for introductory and intermediate-level courses. It discusses problems related to interactions between electron spins in a layered material, measurements using a SQUID magnetometer, and magnetic fields produced by superconducting magnets. Solutions to the problems are also provided.
This document provides an overview of Module 1 of General Physics 2 for Quarter 3. It includes the development team for the module and the key learning competencies, which cover describing charging by rubbing and induction, explaining electron transfer in charging by rubbing, and calculating electric force and field using Coulomb's law. The document then provides introductions to the basic concepts of electrostatics, including how bodies get charged through rubbing or induction. It also explains Coulomb's law and how to calculate electric force and field. Sample problems are provided as examples. Later sections discuss related topics like electric flux and Gauss's law, with more sample problems. A set of activities for students is also included.
1. The document discusses the subatomic particles that make up atoms, including electrons, protons, and neutrons. It defines related terms like atomic number and mass number.
2. Atoms can form isotopes that have the same number of protons but different numbers of neutrons. The forces that hold atoms together are electric forces between the positively charged protons and negatively charged electrons.
3. Oppositely charged particles attract, while similarly charged particles repel, according to the rules of electric force. This balance of forces is what allows atoms to form without collapsing in on themselves or flying apart.
Electrical Charges and Coulomb's Law.pptxReymartSupleo
1) The document discusses electrical charges and Coulomb's law. It defines electric charge, the two types of charges (positive and negative), and how like charges repel and unlike charges attract based on Coulomb's law.
2) Coulomb's law gives the formula for the magnitude of the electrostatic force between two point charges, defining it as directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
3) Several examples show how to calculate the electrostatic force between charges using Coulomb's law and solving for unknown distances or forces.
Electrostatics covers the properties of electric charges, electrostatic force, and electric fields. Key points include:
- There are two types of electric charges: positive and negative. Like charges repel and unlike charges attract.
- Charge is quantized and conserved. It exists in integer multiples of the fundamental unit, e.
- Coulomb's law describes the electrostatic force between two point charges. The force is proportional to the product of the charges and inversely proportional to the square of the distance between them.
- Electric fields are vector fields that exist around charged objects. The electric field strength is defined as the force per unit charge. Field lines are used to represent electric fields graphically.
This document provides an overview of a physics unit on semiconductors and superconductivity. It includes 20 slides on semiconductors covering topics like intrinsic and extrinsic semiconductors, doping, carrier concentrations, and the Hall effect. It also includes 37 slides on superconductivity covering critical temperature, Meissner effect, types of superconductors, flux quantization, Cooper pairs, and applications of the Josephson effect and superconductors in areas like energy transmission and magnetic levitation.
The document is an introduction to periodicity for A-level chemistry students. It discusses the organization of the periodic table by atomic number into rows and columns. It also summarizes trends in various atomic properties across period 3, including atomic radius decreasing due to nuclear charge, ionization energy generally increasing due to nuclear charge but with exceptions, electrical conductivity decreasing for nonmetals with no delocalized electrons, electronegativity increasing with nuclear charge, and melting point generally increasing for metals due to metallic bonding but decreasing for nonmetals due to weaker van der Waals forces.
E-M Effects and Atomic Physics Y11 Physics Rotation 1 2023-24.pptxKristieCorpus
The document provides an overview of magnetism and electromagnetism, describing the properties of magnets including magnetic materials, poles, attraction and repulsion of poles, and how electromagnets work using coils of wire and electric current. It also discusses magnetic fields and how they can be observed using iron filings or small compasses, as well as different types of magnets such as bar magnets and horseshoe magnets.
The document discusses several key concepts in electromagnetism including electric charge, Coulomb's law, and the superposition principle. It provides examples of how to calculate the electric force between two charges using Coulomb's law and how to find the net force on a charge from multiple other charges using the superposition principle. It also gives an example problem of using Newton's laws and electric forces to calculate the charge needed to balance the gravitational force on a hanging charged ball.
introduction,advantage and disadvantage of solar energy,Generation of solar cell: 1st 2nd 3rd generation solar cell , I-V characteristics, working,application, efficiency data and advantage solar cell.
The document discusses the atomic theory of matter and the development of atomic structure models. It describes John Dalton's atomic theory which stated that elements are composed of atoms that are unique and atoms are neither created nor destroyed in chemical reactions. The discovery of the electron by J.J. Thompson and experiments by Robert Millikan and Ernest Rutherford helped develop the modern atomic structure model of a small, dense nucleus surrounded by electrons. The document also discusses isotopes, atomic numbers, mass numbers, and how the periodic table is arranged based on atomic structure.
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...Advanced-Concepts-Team
Presentation in the Science Coffee of the Advanced Concepts Team of the European Space Agency on the 07.06.2024.
Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
Abstract:
In this talk I will describe some recent ideas to find gravitational waves from supermassive black holes or of primordial origin by studying their secular effect on the orbital motion of the Moon or satellites that are laser ranged.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...Travis Hills MN
By harnessing the power of High Flux Vacuum Membrane Distillation, Travis Hills from MN envisions a future where clean and safe drinking water is accessible to all, regardless of geographical location or economic status.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
Immersive Learning That Works: Research Grounding and Paths Forward
PHYS632_C1_22_Charge.ppt
1. Summer July 04 PHYS632 E&M 1
Lecture 1 Charge Chp. 22
•Cartoon - Charge is analogous to mass
•Opening Demo - Large Van de Graaff
•Warm-up problem
•Physlet - static cling
•Topics
–What is electric charge? Point objects, Size. Atomic model
–Methods of charging objects. Friction,Contact, Induction, Machines
–Instruments to measure charge
–Quantization of charge and conservation of charge
–Coulombs Law and examples
–Principle of superposition and examples
•List of Demos
–Teflon, glass, wood, spinner, and silk and UVa electroscope and leaf electroscope
–Pivoting 2 x 4 balanced on glass illustrates strength of temporary induced charge
–Use two metal spheres, measure charge on it, show induction of opposite charge
–Two hanging pith balls with double string plus calculation
–Electrophorous two aluminum pie plates with styrofoam and handle,
–Electrometer and Faraday cage
–Small Van de Graaff Generator, lightning rod, electroscope, electric wind,Fluorescen
–Kelvin water drop generator
2. Summer July 04 PHYS632 E&M 2
Introduction
• “In the matter of physics, the first lessons should
contain nothing but what is experimental and
interesting to see. A pretty experiment is in itself
more valuable than 20 formulae.” Albert Einstein
3. Summer July 04 PHYS632 E&M 3
Charged Hair Van de Graaff Demo
• How does this gadget produce a mini-lightning bolt?
• What upward forces are keeping your hair up?
• How are these forces produced?
• Why do the hair strands spread out from each other?
• Why do they spread out radially from the head?
• Is hair a conductor or insulator? How can we find out? Does it depend if
is wet or dry.
• To understand what is going on we need a model of electricity.
•Start out with VDG hair raising demo: Need a female teacher to come
forward. Take a picture.
4. Summer July 04 PHYS632 E&M 4
Introduction Continued
•What is charge? How do we visualize it. What is the model. We only know
charge exists because in experiments electric forces cause objects to move.
–Show cartoon comparing mass and charge
•Electrostatics: study of electricity when the charges are not in
motion. Good place to start studying E&M because there are
lots of demonstrations.
•Atomic Model:
- Show overhead
5. Summer July 04 PHYS632 E&M 5
Some preliminaries
• Electron: Considered a point object with radius less than 10-18 meters with electric
charge e= -1.6 x 10 -19 Coulombs (SI units) and mass me= 9.11 x 10 - 31 kg
• Proton: It has a finite size with charge +e, mass mp= 1.67 x 10-27 kg and with radius
– 0.805 +/-0.011 x 10-15 m scattering experiment
– 0.890 +/-0.014 x 10-15 m Lamb shift experiment
• Neutron: Similar size as proton, but with total charge = 0 and mass mn=
– Positive and negative charges exists inside the neutron
• Pions: Smaller than proton. Three types: + e, - e, 0 charge.
– 0.66 +/- 0.01 x 10-15 m
• Quarks: Point objects. Confined to the proton and neutron,
– Not free
– Proton (uud) charge = 2/3e + 2/3e -1/3e = +e
– Neutron (udd) charge = 2/3e -1/3e -1/3e = 0
– An isolated quark has never been found
6. Summer July 04 PHYS632 E&M 6
Model of electricity
1cm long and a radius of 0,005 cm
Copper atom:
Z=29(protons), N= 34(neutrons),
29 Electrons
Question: What is the electrical charge in the material that we are
talking about? What is responsible for the conduction of electricity?
How many electrons are moving about?
Carbon or diamond
Copper (Face Centered Cube)
Consider solid material like a piece of copper wire. The proton core
is fixed in position in a lattice like structure. In a conductor, some electrons
are free to move about. How many electrons are there free to move about?
7. Summer July 04 PHYS632 E&M 7
More preliminaries
Atoms: Below on the left are two widely separated copper
atoms. On the right is shown what happens as they come
closer together to in a lattice.
8. Summer July 04 PHYS632 E&M 8
Comparison of which bands are filled and which are empty to
explain the difference between metals and insulators
In a metal there are electrons in the ground state of the metal that can easily
move to unoccupied levels. In an insulator, there are no free electrons to move
about because they do not have enough energy to jump the band gap Eg.
Other criterion
9. Summer July 04 PHYS632 E&M 9
Methods of Charging Objects:
Friction, Contact, and Induction
• Normally atoms are in the lowest energy state. This means that
the material is electrically neutral. You have the same number of
electrons as protons in the material.
• How do we change this?
• How do we add more electrons than protons?
10. Summer July 04 PHYS632 E&M 10
Charging Insulators by Friction/Rubbing
• Rub two materials together: Show teflon/silk
• Show that there is a net charge on the teflon and silk
using aluminum leaf electroscope.
14. Summer July 04 PHYS632 E&M 14
Explain Electrostatic kit for Lab
15. Summer July 04 PHYS632 E&M 15
Two teflon rods on spinner
- - -
- - -
16. Summer July 04 PHYS632 E&M 16
Summary
•Silk(+) on teflon(-)
•Silk (-) on acrylic (+)
•Wood doesn’t charge
•Charged objects always attract neutral objects
•Show Triboelectric series
•Not only chemical composition important, structure of surface is
important - monolayer of molecules involved, quantum effect.
(nanotechnology)
17. Summer July 04 PHYS632 E&M 17
Triboelectric series
http://www.sciencejoywagon.com/physicszone/lesson/07elecst/static/triboele.htm
18. Summer July 04 PHYS632 E&M 18
Charged rods on spinner/similar to picture in book
19. Summer July 04 PHYS632 E&M 19
Charging by Contact / Induction using
conductors
• Show electronic electroscope (EE) with cage: gives magnitude
and sign of charge. Use teflon and acrylic
to show difference
• Show uniformity of charge around sphere using EE.
• Show induction:
– using conducting spheres and EE
– using electroscope
– electrophorus
– using water stream deflection need to know about electric dipoles
• Show hanging charged/conducting pith ball: first attraction by
induction, then contact, then conduction of charge, then
repulsion
20. Summer July 04 PHYS632 E&M 20
Show Uniform Distribution of Charge on Sphere
using EE
21. Summer July 04 PHYS632 E&M 21
Show induction using two conducting spheres and EE
22. Summer July 04 PHYS632 E&M 22
Show Induction using electroscope (small effect)
23. Summer July 04 PHYS632 E&M 23
Electrophorous(Induction)
http://www.physicsclassroom.com/mmedia/estatics/epn.html
• Rub foam surface with silk.
• Place aluminum pan with insulating handle on to charged surface.
•Touch aluminum pan to ground it.
•Separate pans. What is the charge on the pan?
•Repeat indefinitely
- - - - - -
- - - - - - ++++++++
- - - - - - - - -
++++++ ++++++
- - - - - -
Key: Negative charge(electrons), immobile on foam surface, repels electrons in conducting
aluminum pie plate. When you ground the aluminum pan, those electrons are repelled to
ground leaving the pie plate positively charged. Discharge pie plate and then repeat process
as long as foam is charged
Ground
24. Summer July 04 PHYS632 E&M 24
Conservation of charge
• Rubbing does not create charge, it is transferred from object to
another
• Teflon negative - silk positive
• Acrylic positive - silk negative
• Nuclear reactions 0 = e+ + e-
• Radioactive decay 238U92 = 234Th90 + 4He2
• High energy particle reactions e- + p+ = e- + p+ + n0
25. Summer July 04 PHYS632 E&M 25
Summary:
Electrostatics is based on 4 four empirical
facts
• Conservation of charge
• Quantization of charge
• Coulombs Law
• The principle of superposition
26. Summer July 04 PHYS632 E&M 26
What is meant by quantization of charge?
• Discovered in 1911 by Robert A. Milikan in the oil drop
experiment
• The unit of charge is so tiny that we will never notice it comes in
indivisible lumps.
• Example: Suppose in a typical experiment we charge an object
up with a nanoCouloumb of charge (10-9 C). How many
elementary units of charge is this?
• Q=N*e so N= Q/e = 10-9 C/ 1.6*10 -19 C/e = 6*109 = six billion
units of charge or 6 billion electrons.
27. Summer July 04 PHYS632 E&M 27
Coulombs Law
• In 1785 Charles Augustin Coulomb reported in the Royal
Academy Memoires using a torsion balance two charged
mulberry pithballs repelled each other with a force that is
inversely proportional to the distance.
– F = kq1q2/r2 where k=8.99*109 Nm2/C2 in SI unit
k ~ 1010 Nm2/C2
q2
q1 r Repulsion
Repulsion
Attraction
+ +
+
-
- -
Lab
Experiment
Spheres same
as points
28. Summer July 04 PHYS632 E&M 28
Uniformly charged metal spheres
of Radius R
+
+ +
+
+
+ +
+
r
q q
F=kq2/r2
++
++
++
++ F~kq2/(r+R)2
R
29. Summer July 04 PHYS632 E&M 29
Coulombs Law examples
(equivalent to a weight of something with a mass of 10-5 kg = 10-2 gm or
10 mg - long strand of hair)
1 nC
1 nC 1 cm
q2
q1 r
•What is the force between two positive charges each 1 nanoCoulomb
1cm apart in a typical demo? Why is the force so weak here?
F = kq1q2/r2
F =1010 Nm2/C2 (10-9 C)2/ 10-4m2 =10-4 N
Repulsion
30. Summer July 04 PHYS632 E&M 30
Coulombs Law examples
– The force is F =1010 (1.4*10 5)2 =2.0*1020 N
What is the force between two 3 gm pennies one meter apart if we remove
all the electrons from the copper atoms? (Modeling)
What is their acceleration as they separate?
–F= kq1q2/r2 = 1010 *q2/12 So what is q?
The atom Cu has 29 protons and a 3 gm penny has
(3/63.5) * 6*1023 =3* 1022 atoms.
–The total charge is q = 29*3*1022 *1.6*10 -19 = 1.4*105 C
a= F/m = 2.0*1020 / 3*10-3 = 0.7*1023 m/s2
31. Summer July 04 PHYS632 E&M 31
Principle of Superposition
• In the previous example we tacitly assumed that the forces
between nuclei simply added and did not interfere with each
other. That is the force between two nuclei in each penny is the
same as if all the others were not there. This idea is correct and
is referred to as the Principle of Superposition.
• Another Example
– Three charges lie on the x axis: q1=+25 nC at the origin, q2= -12 nC
at x =2m, q3=+18 nC at x=3 m. What is the net force on q1? We
simply add the two forces keeping track of their directions. Let a
positive force be one in the + x direction.
– F =- k q1 (q2 / 22 + q3 / 32)
– = -1010 25*10-9 (-12*10-9 /4 + 18*10-9 /9)
– = +2.5*10-7 N.
1 2
x
3
32. Summer July 04 PHYS632 E&M 32
Example
Question: What is the net force on q1 and in what direction?
2 cm
q2= + 1 nC
q1= + 1 nC
q3= - 2 nC
y
x
1 cm
Hint : Find x and y components of force on q1 due to q2 and q3
and add them up.
Fq1,q
2
Fq1,q3
33. Summer July 04 PHYS632 E&M 33
Example Cont.
2 cm
q2= + 1 nC
q1= + 1 nC
q3= - 2 nC
y
x
1 cm
x - y Components of force due to q2
Fx= - 1010 (10-9 )2/ (10-2)2 = -1x10-4 N
F = kq1q2/r2
Fy= 0
Magnitude of Force due to q3
IFI = + 1010 (2x10-9 )(1x10-9) / (5x10-4 )= 0.40x10-4 N
q
q = atan 2/1 = 63.43
deg
Fx= F cos q = 0.40 N cos 63.43=(0.4)( 0.447)
= + 0.179x10-4 N
Fy= F sin q = 0.40 N sin 63.43 = (0.4)( 0.894)
= 0.358x10-4 N
Fy
Fx
F
q
Sum Fx = - 1x10-4 + 0.179x 10-4 = - 0.821x10-4 N
Sum Fy = 0 + 0.358 x10-4 N = 0.358x10-4 N
Fne
t
q1
1
q1= atan Fy/Fx=atan 0.358x10-4/ - 0.821x10-4 = 23.6 deg
+
+
Sign convention
x - y Components of force due to q3
34. Summer July 04 PHYS632 E&M 34
In an atom can we neglect the gravitational force between
the electrons and protons? What is the ratio of Coulomb’s
electric force to Newton’s gravity force for 2 electrons
separated by a distance r ?
– Fc/ Fg = 1010 Nm2/C2 (1.6*10 -19C)2 /6.67*10-11 Nm2/Kg2 (9.1*10-31 Kg)2
– = 4.6*1042
– Coulomb / Gravity = 4.6*1042
– Huge ratio and pure number.
q
q r m
m r
Fc= kee/r2 Fg=Gmm/r2
Fc/ Fg = ke2 /Gm2
35. Summer July 04 PHYS632 E&M 35
Why are neutral objects always attracted to positive
or negative charged objects.
For example:
•Rubbed balloon is attracted to wall
•Comb is attracted to small bits of paper
•Clothes in the dryer stick together.
1. Put wood on the spinner and place charged teflon
and plastic rods near it. Try a twig from a tree.
3. Place charged rod on spinner and place your hand
Near it.
2. Put the 2 x 4 on a curved glass surface and try it.
What is the explanation of all of these phenomena?
36. Summer July 04 PHYS632 E&M 36
Explanation: The neutral objects atoms and molecules orient
themselves in the following way so that the Coulomb forces due to attraction are
greater than those due to repulsion because the latter are further away. (Inverse square
Law)
+
+
+
+
+
+
Acrylic Rod Wooden block
+
+
+
+
+
+
-
-
-
-
-
-
+
+
+
+
+
+
Acrylic Rod Wooden block
F= kq1q2/r2
Attraction
Repulsion
Attractive forces >> Repulsive Forces
38. Summer July 04 PHYS632 E&M 38
What is the real distribution of charge along a conductor like a
wire or tube? How does the charged UVa electroscope really
work?
39. Summer July 04 PHYS632 E&M 39
How the electroscope works? How is charge
distributed along a conducting rod?
Am J. Phys. 65,846(1977)
+++
+++
+++
+++
Model
41. Summer July 04 PHYS632 E&M 41
Show hanging charged/conducting pith ball:
first attraction by induction, then contact, then
conduction of charge, then repulsion
42. Summer July 04 PHYS632 E&M 42
Find charge Q on two pith balls separated by distance d
Change to proper
units:m,kg,s,N,C
Suppose d =2 cm, L=20 cm, and
m = 0.20 g, Find Q in nanoCoulombs.
43. Summer July 04 PHYS632 E&M 43
Warm up set 1
1. HRW6 22.P.019. [52295] What is the total charge in coulombs of 83.0 kg of electrons?
2. HRW6 22.P.023. [52297] How many electrons would have to be removed from a coin to leave
it with a charge of +1.5 10-7 C?
Number of electrons = 83.0 kg/9.11*10-31 kg = 9.11 *10+31 electrons
Number of electrons = 1.5*10 -7 C/ 1.60*10-19C = 9.38e+11C = 9.38 10+11 C
Q= 9.11 *10+31 *-1.60*10-19C =-1.46e+13 C= =-1.46 10+13C
Assume the coin is neutral.
44. Summer July 04 PHYS632 E&M 44
•Otto von Guericke in 1660 charged a 7” Sulphur sphere
•Wimshurst Machine (1880)
•Van de Graaff Generator (1931)
•Lord Kelvin Water Drop Generator (Early 18’th century)
Charging Objects using Electrostatic Machines
45. Summer July 04 PHYS632 E&M 45
Otto von Guericke in 1660 charged a 7” Sulphur sphere
• The Sulphur Ball: Otto von Guericke (1602-1686) who became famous for his Magdeburg
vacuum experiments invented a first simple electrostatic generator. It was made of a sulphur
ball which rotated in a wooden cradle. The ball itself was rubbed by hand. As the principles of
electric conduction had not been discovered yet, von Guericke transported the charged
sulphur ball to the place where the electric experiment should happen. Guericke made the
ball by pouring molten sulphur into a hollow glass sphere. After the sulphur was cold, the
glass hull was smashed and removed. Some day, a researcher found out that the empty
glass sphere itself provided the same results.
46. Summer July 04 PHYS632 E&M 46
Lord Kelvin Water Drop Generator (Early 18’th century)
http://www.angelfire.com/ak/egel/kelv1.html
+ +
47. Summer July 04 PHYS632 E&M 47
---
-|||||-
/
+||+
+ -----
+o+
+o+
+
-
-o-
-o-
-
Kelvin Water Drop Generator
- -
48. Summer July 04 PHYS632 E&M 48
Wimshurst Machine
The Englishman, James
Wimshurst (1832-1903), spent
most of his professional career
working with the shipping
industry as a surveyor and
evaluator of ships, serving as
the consulting engineer for the
British Board of Trade.. At the
same time he had a parallel
career in science. We know
him for his work with
electrostatic generators in the
early 1880s, when he
improved Voss' electrostatic
generator.
In Wimshurst design, the
disks contra-rotate. The metal
foil sectors on the disks induce
charges on each other, which
are picked off with metal
brushes and stored in Leiden
jars.
49. Summer July 04 PHYS632 E&M 49
Van de Graaff Accelerator
http://chem.ch.huji.ac.il/~eugeniik/history/graaff.
Robert Van de Graaff Generator (1931) Tuscaloosa, Alabama