Download Electricity and Magnetism - Lecture Slides | PHYS 102 and more Study notes Physics in PDF only on Docsity! 1 Physics 102: Lecture 1, Slide 1 Welcome to Physics 102! • Electricity + Magnetism • Optics • Atomic Physics • Nuclear Physics • Relativity http://online.physics.uiuc.edu/courses/phys102/ 2 Physics 102: Lecture 1, Slide 2 Meet the Lecturer • Tim Stelzer t-stelzer@uiuc.edu • Research – Elementary Particle Experimental Physics http://online.physics.uiuc.edu/courses/phys102/ 5 Physics 102: Lecture 1, Slide 5 Reading & Lecture • Do it! • Answer preflights 50/1000 points – 2 points for honest attempt at preflight. – Must do the entire preflight to earn any credit 6 Physics 102: Lecture 1, Slide 6 P102 Lectures • Not everything you need! – Concepts, Connections, Motivation – Comprehensive Textbook – Calculations Homework + Discussion – Hands-On Lab • Taking Notes – Lecture notes will be available at bookstore or online – Some key pieces for you to fill in 7 Physics 102: Lecture 1, Slide 7 Origin of Charge • Charge is an intrinsic property of matter • Two types: – Positive Charge: Protons – Negative Charge: electrons – Opposites Attract! (likes repel) • Atoms are neutral – Negatively charged electrons “orbit” r~10-10 m – Positively charged central nucleus r~10-15 m 10 Physics 102: Lecture 1, Slide 10 ACTS • A negatively charged rod is used to charge an electroscope by induction. What is the resulting net charge on the electroscope? 1) positive 2) zero 3) negative • If the conducting electroscope were replaced by an insulating ball and then charged by induction as above, what would be the net charge on the ball. 1) positive 2) zero 3) negative 11 Physics 102: Lecture 1, Slide 11 + - r = 1x10-10 m Qp=1.6x10-19 C Qe = -1.6x10-19 C Coulomb’s Law • Magnitude of the force between charges q1 and q2 separated a distance r: • F = k q1q2/r2 k = 9x109 Nm2/C2 • Force on electron in Hydrogen atom 12 Physics 102: Lecture 1, Slide 12 ACT: Coulomb’s Law • What is the direction of the force on the proton due to the electron? (1) Left (2) Right (3) Zero • What is the magnitude of the force on the proton due to the electron? + - r = 1x10-10 m qp=1.6x10-19 C qe = -1.6x10-19 C F= _______ N F
