logging in or signing up electrostatics powerpoint lkaluzny6582 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 4248 Category: Education License: All Rights Reserved Like it (2) Dislike it (0) Added: September 07, 2009 This Presentation is Public Favorites: 3 Presentation Description These notes are for Physics 3 students. They give background on static electricity Comments Posting comment... By: didithasensi (27 month(s) ago) Well-organized, very neat presentation. I like it very much. I just wish you had included uniform electric field as well. But this is very good. Thanks for sharing. Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Electrostatics : Electrostatics Slide 2: http://www.nearingzero.net (nz192.jpg) A Bit of History : A Bit of History Ancient Greeks Observed electric and magnetic phenomena as early as 700 BC Found that amber, when rubbed, became electrified and attracted pieces of straw or feathers Magnetic forces were discovered by observing magnetite attracting iron A Bit More History : A Bit More History William Gilbert 1600 Found that electrification was not limited to amber Charles Coulomb 1785 Confirmed the inverse square relationship of electrical forces History Final : History Final Hans Oersted 1820 Compass needle deflects when placed near an electrical current Michael Faraday A wire moved near a magnet, an electric current is observed in the wire Properties of Electric Charges : Properties of Electric Charges Two types of charges exist They are called positive and negative Named by Benjamin Franklin Like charges repel and unlike charges attract one another Question #2 : Question #2 The charge on sphere 2 is three times the charge on sphere 1. Which force diagram is correct? (e) is none of the others. Answer #2: (d) : Answer #2: (d) The charge on sphere 2 is three times the charge on sphere 1. Which force diagram is correct? (e) is none of the others. More Properties of Charge : More Properties of Charge Nature’s basic carrier of positive charge is the proton Protons do not move from one material to another because they are held firmly in the nucleus Nature’s basic carrier of negative charge is the electron Gaining or losing electrons is how an object becomes charged Electrons are found in the electron cloud outside of the nucleus Neutrons are electrically neutral and have no charge and are found inside the nucleus Bohr Model of the Atom : Bohr Model of the Atom More Properties of Charge : More Properties of Charge Electric charge is always conserved Charge is not created, only exchanged Objects become charged because negative charge is transferred from one object to another Properties of Charge, final : Properties of Charge, final Charge is quantized All charge is a multiple of a fundamental unit of charge, symbolized by e Electrons have a charge of –e Protons have a charge of +e The SI unit of charge is the Coulomb (C) e = 1.602 x 10-19 C Conductors : Conductors Conductors are materials in which the electric charges move freely Copper, aluminum and silver are good conductors When a conductor is charged in a small region, the charge readily distributes itself over the entire surface of the material Insulators : Insulators Insulators are materials in which electric charges do not move freely Glass and rubber are examples of insulators When insulators are charged by rubbing, only the rubbed area becomes charged There is no tendency for the charge to move into other regions of the material Semiconductors : Semiconductors The characteristics of semiconductors are between those of insulators and conductors Silicon and germanium are examples of semiconductors Charging… : Charging… Two ways Electrification by Contact (EBC) Induction Charging by Friction : Charging by Friction Self-explanatory… (demo) Charging by EBC : Charging by EBC A charged object (the rod) is physically touches the other uncharged, object (the sphere) The same type of charge is CONDUCTED from the rod to the sphere Charging by Induction : Charging by Induction Charging by Induction : Charging by Induction Charging by Induction : Charging by Induction NO physical contact between between charged & uncharged object OPPOSITE charged is INDUCED Question #3 : Question #3 An alpha particle with two positive charges and a less-massive electron with a single negative charge are attracted to each other. The force on the electron is: Greater than that on the alpha particle Less than that on the alpha particle Same as that on the alpha particle I haven’t a clue… Answer #3: (c) Same : Answer #3: (c) Same The force on the electron the same as that on the alpha particle - Newton’s Third Law. Question #4 : Question #4 An alpha particle with two positive charges and a less-massive electron with a single negative charge are attracted to each other. The particle with the most acceleration is the Alpha particle Electron Neither - they have the same acceleration I haven’t a clue… Answer #4: (b) Electron : Answer #4: (b) Electron The particle with the most acceleration is the ELECTRON. Newton’s Second Law (F=ma) Question #5 : Question #5 An alpha particle with two positive charges and a less-massive electron with a single negative charge are attracted to each other. As the particles get closer to each other, each experiences an increase in: force speed acceleration All of these None of these Answer #5: (d) ALL : Answer #5: (d) ALL As the particles get closer, the FORCE and thus the ACCELERATION and also the SPEED Coulomb’s Law : Coulomb’s Law Governs forces and charges, ke is called the Coulomb Constant ke = 8.99 x 109 N m2/C2 Typical charges can be in the µC range Remember that force is a vector quantity Question #6 : Question #6 If q1 = +20 C and q2 = +10 C and the two charges are 3 meters apart, what is the MAGNITUDE of the force between them? 0.2 N 0.6 N 22.22 N 2.0 x 10 11 N I don’t have a clue Answer #6: (a) 0.2 N : Answer #6: (a) 0.2 N Vector Nature of Electric Forces : Vector Nature of Electric Forces Two point charges are separated by a distance r The like charges produce a repulsive force between them The force on q1 is equal in magnitude and opposite in direction to the force on q2 Vector Nature of Forces, cont. : Vector Nature of Forces, cont. Two point charges are separated by a distance r The unlike charges produce a attractive force between them The force on q1 is equal in magnitude and opposite in direction to the force on q2 Question #7 : Question #7 If q1 = +20 C and q2 = +10 C and the two charges are 3 meters apart, what is the DIRECTION of the force between them? Away from each other Towards each other One chases the other Nothing - they don’t move at all I don’t have a clue Answer #7: (a) Away : Answer #7: (a) Away If q1 = +20 C and q2 = +10 C and the two charges are 3 meters apart, what is the DIRECTION of the force between them? Like charges repel Electrical Field : Electrical Field An electric field is said to exist in the region of space around a charged object When another charged object enters this electric field, the field exerts a force on the second charged object Electric Field, cont. : Electric Field, cont. A charged particle, with charge Q, produces an electric field in the region of space around it A small test charge, qo, placed in the field, will experience a force Electric Field : Electric Field Mathematically, The electric field is a vector quantity Question #9 : Question #9 What is the magnitude of the electric field 0.50 meters away from a -3C point charge? 1.08 x 105 N/C -1.08 x 105 N/C 5.4 x 104 N/C -5.4 x 104 N/C I don’t have a clue… Answer #9: (a) 1.08x105 N/C : Answer #9: (a) 1.08x105 N/C What is the magnitude of the electric field 0.50 meters away from a -3C point charge? 1.08 x 105 N/C -1.08 x 105 N/C 5.4 x 104 N/C -5.4 x 104 N/C I don’t have a clue… Question #9 : Question #9 What is the magnitude of the electric field 0.50 meters away from a -3C point charge? 1.08 x 105 N/C -1.08 x 105 N/C 5.4 x 104 N/C -5.4 x 104 N/C I don’t have a clue… Direction of Electric Field : Direction of Electric Field The electric field produced by a negative charge is directed toward the charge A positive test charge would be attracted to the negative source charge Direction of Electric Field, cont : Direction of Electric Field, cont The electric field produced by a positive charge is directed away from the charge A positive test charge would be repelled from the positive source charge Question #10 : Question #10 What is the electrostatic force acting on a 2 nC charge placed in a 335 N/C electric field? 0 N 6.7 x 10-4 N 6.7 x 10-7 N 6.7 N I don’t have a clue… Answer #10: (c) 6.7 x 10-7 N : Answer #10: (c) 6.7 x 10-7 N What is the electrostatic force acting on a 2 nC charge placed in a 335 N/C electric field? Electric Field Lines : Electric Field Lines A convenient aid for visualizing electric field patterns is to draw lines pointing in the direction of the field vector at any point These are called electric field lines and were introduced by Michael Faraday Electric Field Lines, cont. : Electric Field Lines, cont. The field lines are related to the field by The electric field vector, E, is tangent to the electric field lines at each point The number of lines per unit area through a surface perpendicular to the lines is proportional to the strength of the electric field in a given region Electric Field Line Patterns : Electric Field Line Patterns Point charge The lines radiate equally in all directions For a positive source charge, the lines will radiate outward Electric Field Line Patterns : Electric Field Line Patterns For a negative source charge, the lines will point inward Electric Field Line Patterns : Electric Field Line Patterns An electric dipole consists of two equal and opposite charges The high density of lines between the charges indicates the strong electric field in this region Electric Field Line Patterns : Electric Field Line Patterns Two equal but like point charges At a great distance from the charges, the field would be approximately that of a single charge of 2q The bulging out of the field lines between the charges indicates the repulsion between the charges The low field lines between the charges indicates a weak field in this region Electric Field Patterns : Electric Field Patterns Unequal and unlike charges Note that two lines leave the +2q charge for each line that terminates on -q Electric Field Lines : Electric Field Lines Electric Field Lines : Electric Field Lines Electric Field Lines : Electric Field Lines Electrostatics : Electrostatics The End… You do not have the permission to view this presentation. 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electrostatics powerpoint lkaluzny6582 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 4248 Category: Education License: All Rights Reserved Like it (2) Dislike it (0) Added: September 07, 2009 This Presentation is Public Favorites: 3 Presentation Description These notes are for Physics 3 students. They give background on static electricity Comments Posting comment... By: didithasensi (27 month(s) ago) Well-organized, very neat presentation. I like it very much. I just wish you had included uniform electric field as well. But this is very good. Thanks for sharing. Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Electrostatics : Electrostatics Slide 2: http://www.nearingzero.net (nz192.jpg) A Bit of History : A Bit of History Ancient Greeks Observed electric and magnetic phenomena as early as 700 BC Found that amber, when rubbed, became electrified and attracted pieces of straw or feathers Magnetic forces were discovered by observing magnetite attracting iron A Bit More History : A Bit More History William Gilbert 1600 Found that electrification was not limited to amber Charles Coulomb 1785 Confirmed the inverse square relationship of electrical forces History Final : History Final Hans Oersted 1820 Compass needle deflects when placed near an electrical current Michael Faraday A wire moved near a magnet, an electric current is observed in the wire Properties of Electric Charges : Properties of Electric Charges Two types of charges exist They are called positive and negative Named by Benjamin Franklin Like charges repel and unlike charges attract one another Question #2 : Question #2 The charge on sphere 2 is three times the charge on sphere 1. Which force diagram is correct? (e) is none of the others. Answer #2: (d) : Answer #2: (d) The charge on sphere 2 is three times the charge on sphere 1. Which force diagram is correct? (e) is none of the others. More Properties of Charge : More Properties of Charge Nature’s basic carrier of positive charge is the proton Protons do not move from one material to another because they are held firmly in the nucleus Nature’s basic carrier of negative charge is the electron Gaining or losing electrons is how an object becomes charged Electrons are found in the electron cloud outside of the nucleus Neutrons are electrically neutral and have no charge and are found inside the nucleus Bohr Model of the Atom : Bohr Model of the Atom More Properties of Charge : More Properties of Charge Electric charge is always conserved Charge is not created, only exchanged Objects become charged because negative charge is transferred from one object to another Properties of Charge, final : Properties of Charge, final Charge is quantized All charge is a multiple of a fundamental unit of charge, symbolized by e Electrons have a charge of –e Protons have a charge of +e The SI unit of charge is the Coulomb (C) e = 1.602 x 10-19 C Conductors : Conductors Conductors are materials in which the electric charges move freely Copper, aluminum and silver are good conductors When a conductor is charged in a small region, the charge readily distributes itself over the entire surface of the material Insulators : Insulators Insulators are materials in which electric charges do not move freely Glass and rubber are examples of insulators When insulators are charged by rubbing, only the rubbed area becomes charged There is no tendency for the charge to move into other regions of the material Semiconductors : Semiconductors The characteristics of semiconductors are between those of insulators and conductors Silicon and germanium are examples of semiconductors Charging… : Charging… Two ways Electrification by Contact (EBC) Induction Charging by Friction : Charging by Friction Self-explanatory… (demo) Charging by EBC : Charging by EBC A charged object (the rod) is physically touches the other uncharged, object (the sphere) The same type of charge is CONDUCTED from the rod to the sphere Charging by Induction : Charging by Induction Charging by Induction : Charging by Induction Charging by Induction : Charging by Induction NO physical contact between between charged & uncharged object OPPOSITE charged is INDUCED Question #3 : Question #3 An alpha particle with two positive charges and a less-massive electron with a single negative charge are attracted to each other. The force on the electron is: Greater than that on the alpha particle Less than that on the alpha particle Same as that on the alpha particle I haven’t a clue… Answer #3: (c) Same : Answer #3: (c) Same The force on the electron the same as that on the alpha particle - Newton’s Third Law. Question #4 : Question #4 An alpha particle with two positive charges and a less-massive electron with a single negative charge are attracted to each other. The particle with the most acceleration is the Alpha particle Electron Neither - they have the same acceleration I haven’t a clue… Answer #4: (b) Electron : Answer #4: (b) Electron The particle with the most acceleration is the ELECTRON. Newton’s Second Law (F=ma) Question #5 : Question #5 An alpha particle with two positive charges and a less-massive electron with a single negative charge are attracted to each other. As the particles get closer to each other, each experiences an increase in: force speed acceleration All of these None of these Answer #5: (d) ALL : Answer #5: (d) ALL As the particles get closer, the FORCE and thus the ACCELERATION and also the SPEED Coulomb’s Law : Coulomb’s Law Governs forces and charges, ke is called the Coulomb Constant ke = 8.99 x 109 N m2/C2 Typical charges can be in the µC range Remember that force is a vector quantity Question #6 : Question #6 If q1 = +20 C and q2 = +10 C and the two charges are 3 meters apart, what is the MAGNITUDE of the force between them? 0.2 N 0.6 N 22.22 N 2.0 x 10 11 N I don’t have a clue Answer #6: (a) 0.2 N : Answer #6: (a) 0.2 N Vector Nature of Electric Forces : Vector Nature of Electric Forces Two point charges are separated by a distance r The like charges produce a repulsive force between them The force on q1 is equal in magnitude and opposite in direction to the force on q2 Vector Nature of Forces, cont. : Vector Nature of Forces, cont. Two point charges are separated by a distance r The unlike charges produce a attractive force between them The force on q1 is equal in magnitude and opposite in direction to the force on q2 Question #7 : Question #7 If q1 = +20 C and q2 = +10 C and the two charges are 3 meters apart, what is the DIRECTION of the force between them? Away from each other Towards each other One chases the other Nothing - they don’t move at all I don’t have a clue Answer #7: (a) Away : Answer #7: (a) Away If q1 = +20 C and q2 = +10 C and the two charges are 3 meters apart, what is the DIRECTION of the force between them? Like charges repel Electrical Field : Electrical Field An electric field is said to exist in the region of space around a charged object When another charged object enters this electric field, the field exerts a force on the second charged object Electric Field, cont. : Electric Field, cont. A charged particle, with charge Q, produces an electric field in the region of space around it A small test charge, qo, placed in the field, will experience a force Electric Field : Electric Field Mathematically, The electric field is a vector quantity Question #9 : Question #9 What is the magnitude of the electric field 0.50 meters away from a -3C point charge? 1.08 x 105 N/C -1.08 x 105 N/C 5.4 x 104 N/C -5.4 x 104 N/C I don’t have a clue… Answer #9: (a) 1.08x105 N/C : Answer #9: (a) 1.08x105 N/C What is the magnitude of the electric field 0.50 meters away from a -3C point charge? 1.08 x 105 N/C -1.08 x 105 N/C 5.4 x 104 N/C -5.4 x 104 N/C I don’t have a clue… Question #9 : Question #9 What is the magnitude of the electric field 0.50 meters away from a -3C point charge? 1.08 x 105 N/C -1.08 x 105 N/C 5.4 x 104 N/C -5.4 x 104 N/C I don’t have a clue… Direction of Electric Field : Direction of Electric Field The electric field produced by a negative charge is directed toward the charge A positive test charge would be attracted to the negative source charge Direction of Electric Field, cont : Direction of Electric Field, cont The electric field produced by a positive charge is directed away from the charge A positive test charge would be repelled from the positive source charge Question #10 : Question #10 What is the electrostatic force acting on a 2 nC charge placed in a 335 N/C electric field? 0 N 6.7 x 10-4 N 6.7 x 10-7 N 6.7 N I don’t have a clue… Answer #10: (c) 6.7 x 10-7 N : Answer #10: (c) 6.7 x 10-7 N What is the electrostatic force acting on a 2 nC charge placed in a 335 N/C electric field? Electric Field Lines : Electric Field Lines A convenient aid for visualizing electric field patterns is to draw lines pointing in the direction of the field vector at any point These are called electric field lines and were introduced by Michael Faraday Electric Field Lines, cont. : Electric Field Lines, cont. The field lines are related to the field by The electric field vector, E, is tangent to the electric field lines at each point The number of lines per unit area through a surface perpendicular to the lines is proportional to the strength of the electric field in a given region Electric Field Line Patterns : Electric Field Line Patterns Point charge The lines radiate equally in all directions For a positive source charge, the lines will radiate outward Electric Field Line Patterns : Electric Field Line Patterns For a negative source charge, the lines will point inward Electric Field Line Patterns : Electric Field Line Patterns An electric dipole consists of two equal and opposite charges The high density of lines between the charges indicates the strong electric field in this region Electric Field Line Patterns : Electric Field Line Patterns Two equal but like point charges At a great distance from the charges, the field would be approximately that of a single charge of 2q The bulging out of the field lines between the charges indicates the repulsion between the charges The low field lines between the charges indicates a weak field in this region Electric Field Patterns : Electric Field Patterns Unequal and unlike charges Note that two lines leave the +2q charge for each line that terminates on -q Electric Field Lines : Electric Field Lines Electric Field Lines : Electric Field Lines Electric Field Lines : Electric Field Lines Electrostatics : Electrostatics The End…