tag:blogger.com,1999:blog-5088860151651047897.post1393978160103612168..comments2024-03-25T10:56:59.380-04:00Comments on Jacobs Physics: Just the basics, not the sources, of electric, magnetic fieldsGreg Jacobshttp://www.blogger.com/profile/03854009948036330746noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-5088860151651047897.post-14922115649874974072012-01-18T14:26:02.253-05:002012-01-18T14:26:02.253-05:00I taught it this way in my AP B class this year an...I taught it this way in my AP B class this year and it was received very well. I talked about the gravitational field strength and its units of N/kg and then drew a uniform electric field and asked what units would describe the electric field strength. The "conversation" flowed so easily that I even pulled in a sneak peek at potential energy and work done in moving charge in a uniform field, comparing mgh to qEd. I feel they're on a much sounder footing going into the deeper aspects of electricity.Mr. Bockhttps://www.blogger.com/profile/13918908650906240919noreply@blogger.comtag:blogger.com,1999:blog-5088860151651047897.post-6167399636042481822012-01-15T13:19:01.156-05:002012-01-15T13:19:01.156-05:00Great question... They do ask, because I've be...Great question... They do ask, because I've been so insistent all year that only objects, not nebulous concepts like "gravity," can be the source of forces.<br /><br />I explain that for now, we can call this the force of the electric field on the object, because we do not care what produces the electric field. I tell them that eventually in their study of physics, something must produce that electric field; and the force on the charge is applied by whatever produces the electric field. But for now, since the cause of the electric field is irrelevant, saying "force of the electric field on the charge" is acceptable.<br /><br />GCJGreg Jacobshttps://www.blogger.com/profile/03854009948036330746noreply@blogger.comtag:blogger.com,1999:blog-5088860151651047897.post-10525337478322437362012-01-15T13:15:25.831-05:002012-01-15T13:15:25.831-05:00How do you handle students who ask you what is the...How do you handle students who ask you what is the Newton's 3rd law pair for the force on the charge? And if no one ever asks you, do you ask them?Brad Martsbergernoreply@blogger.comtag:blogger.com,1999:blog-5088860151651047897.post-37971064241067923192011-12-27T17:17:12.779-05:002011-12-27T17:17:12.779-05:00Good question. I'm open to suggestions -- Whe...Good question. I'm open to suggestions -- When I taught out of a text, I instructed students NOT to read about electrostatics. When someone read the text anyway, he invariably was the last to understand the topic.<br /><br />The 5 Steps book (5 Steps to a 5, AP Physics B & C) uses this sequence, and is appropriate reading previous or simultaneous to your class coverage. This is a prep book, not a text, but is nevertheless a good supplement. <br /><br />If anyone can recommend a textbook that uses the "field first" approach to electrostatics, please post here!Greg Jacobshttps://www.blogger.com/profile/03854009948036330746noreply@blogger.comtag:blogger.com,1999:blog-5088860151651047897.post-79888467420963038952011-12-27T16:48:03.416-05:002011-12-27T16:48:03.416-05:00I do like your ideas. But my class this year has m...I do like your ideas. But my class this year has many students who prefer to read book right after, sometimes even before my explanations. What reading sources would you recommend for at least the first couple of days (or a week) of electrostatics? Thanks for the great ideas.Mr. Ohttps://www.blogger.com/profile/15569143292651308436noreply@blogger.comtag:blogger.com,1999:blog-5088860151651047897.post-80164315894911566912011-12-27T10:52:35.068-05:002011-12-27T10:52:35.068-05:00I like the idea of teaching F=qE a lot. You tell s...I like the idea of teaching F=qE a lot. You tell students that if you have a charge, things happen to you. Figuring out the sources is much harder. I like the calc-based intro book we use at my college for how it does exactly that with mag fields. One or even two chapters on the effects of mag fields before getting into how they're formed. Thanks for the great post.Andy Rundquisthttp://arundquist.wordpress.comnoreply@blogger.com