lecture03 - September 6, 2011 Physics for Scientists &...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: September 6, 2011 Physics for Scientists & Engineers 2, Chapter 21 1 Please register your iClicker at http://www.iclicker.com/support/ registeryourclicker/ Include the A when you enter your student ID! Electrostatic Force Coulombs Law e law of electric charges is evidence of a force between any two charges at rest Experiments show that for the electrostatic force exerted by charge 2 ( q 2 ) on charge 1 ( q 1 ), the force on q 1 points toward q 2 if the charges have opposite signs and away from q 2 if the charges have like signs September 6, 2011 Physics for Scientists & Engineers 2, Chapter 21 2 Electrostatic Force Coulombs Law Coulombs Law gives the magnitude of this force as k is Coulombs constant given by We can relate Coulombs constant to the electric permittivity of free space 0 September 6, 2011 Physics for Scientists & Engineers 2, Chapter 21 3 F = k q 1 q 2 r 2 q 1 and q 2 are electric charges r = r 1 r 2 is the distance between the charges k = 8.99 10 9 N m 2 C 2 k = 1 4 , = 8.85 10 12 C 2 N m 2 September 6, 2011 Physics for Scientists & Engineers 2, Chapter 21 5 Force between Two Charges PROBLEM What is the magnitude of the force between two 1.00 C charges 1.00 m apart? SOLUTION is force is approximately the same as 450 loaded Space Shuttles! F = k q 1 q 2 r 2 F = 8.99 10 9 N m 2 C 2 1.00 C ( ) 2 1.00 m ( ) 2 F = 8.99 10 9 N Electrostatic Force Vector Coulombs Law can be written in vector form as September 6, 2011 Physics for Scientists & Engineers 2, Chapter 21 6 F 2 1 = k q 1 q 2 r 3 r 2 r 1 ( )= k q 1 q 2 r 2 r 21 Superposition Principle Consider the force exerted on charge q 3 by two other charges q 1 and q 2 September 6, 2011 Physics for Scientists & Engineers 2, Chapter 21 7 F 1 3 = k q 1 q 3 x 3 x 1 ( ) 2 x F 2 3 = k q 2 q 3 x 2 x 3 ( ) 2 x F net 3 = F 1 3 + F 2 3 September 6, 2011 Physics for Scientists&Engineers 2 10 Example - Forces between Electrons What is relative strength of the force of gravity compared with the electric force for two electrons?...
View Full Document

This note was uploaded on 02/03/2012 for the course MTH 235 taught by Professor Staff during the Fall '11 term at Michigan State University.

Page1 / 20

lecture03 - September 6, 2011 Physics for Scientists &...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online