tag:blogger.com,1999:blog-35187314.post3776491979283157633..comments2020-10-28T05:47:36.658-04:00Comments on Physics Buzz: The Khan Academy -- Virtual Cliffs Notes for Math & Physics (& More!)APS Webmasterhttp://www.blogger.com/profile/05951833208918853453noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-35187314.post-17269363374641204792012-06-13T08:48:50.544-04:002012-06-13T08:48:50.544-04:00khan sb kuch samaj nai aa rai sorry yar..............khan sb kuch samaj nai aa rai sorry yar.............Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-35187314.post-35169768061753592011-05-14T07:25:40.632-04:002011-05-14T07:25:40.632-04:00I do not know about other subjects but I didn'...I do not know about other subjects but I didn't find the Physics lectures upto the mark.<br /><br />http://www.khanacademy.org/v/capacitance?p=Physics<br /><br />In the above lecture Mr. Khan writes <br />E = 2k pie sigma. The thing is he writes an arrow above E (which I can't write here in print) which means he is taking E as a vector. But there is no vector on the right hand side of the equation. In other words this equation implies that a vector quantity is equal to a non vector quantity. That's obviously wrong. <br /><br />http://www.khanacademy.org/v/introduction-to-newton-s-law-of-gravitation?p=Physics<br /><br />Then in this video lecture he says that the gravitational force of attraction between any two objects is to be calculated by taking the distance between the center of masses of the objects in question. Now this method works sometimes (as has worked in his video)but generally speaking its wrong. One can only take the entire mass of an object at its center of mass when he is solving a physical quantity which is a linear function of distance. The rigorous method is to use integral calculus. As a matter of fact Newton invented the integral calculus because he wanted to prove that if you are outside the earth then you may take the entire mass of the earth at its geometric center and then apply the force law and you will get correct results.<br /><br />Though I admire Mr. Khan's website for providing free education world wide but such errors are bound to happen if one is teaching so many subjects. I think one should only concentrate on the field in which he has a good mastery.Syed Farhanhttp://www.physicsacademy.weebly.comnoreply@blogger.comtag:blogger.com,1999:blog-35187314.post-17147423205638647312011-03-25T17:29:16.562-04:002011-03-25T17:29:16.562-04:00The Khan Academy also has all the videos on its ow...The Khan Academy also has all the videos on its own Youtube channel - although I find it easier to navigate the various topics on their own website.<br />But what stands out if yo watch his videos on youtube are the comments people leave.<br />Things like "wow, you explain this so much better than my teacher at school" or "thanks to you I finally understand what I should have learnt years ago in class" are typical.<br />Compared to some commercial, paid-for offerings of math instruction (sorry, have not reviewed any physics), I have found Sal Khan's videos at least on par, if not better.Terry from Math Game Reviewhttp://mathgamereview.comnoreply@blogger.com