Understanding Magnetic Forces on Charged Particles, Slides of Physics

Download Understanding Magnetic Forces on Charged Particles and more Slides Physics in PDF only on Docsity! Magnetic Force Docsity.com Moving Charge  A charge in an electric field is subject to a force. • Charge at rest or in motion • In the direction of field  A charge in a magnetic field is also subject to a force. • Only charges in motion • Perpendicular to force and velocity  E  B v Docsity.com Uniform Field  The magnitude is qvBsin. • q = 1.6 x 10-19 C • v = 5.0 x 106 m/s • B = 3.0 T • Angle between v and B is 30° • F = 1.2 x 10-12 N  The direction is based on a positive charge going down. • Down cross north is east • Force vector points east  An electromagnet produces a 3.0 T uniform magnetic field pointing horizontally north in the gap between its poles.  A proton enters the field heading north at a downward 30° angle with a speed of 5.0 x 106 m/s.  Find the magnitude and direction of the force. Docsity.com Particle Tracks  Particles like electrons and protons turn in a magnetic field.  Tracks are captured on film.  Curvature is related to the velocity. Fermilab photo from the 15’ bubble chamber Docsity.com Circular Path  A charge that moves perpendicular to a uniform field stays perpendicular to the field. • Uniform circular motion  The magnetic force is a centripetal force. a F  qvB r mvF  2 v Field into page r qB mvr  Docsity.com