almost anything for free." That is the tag line of the Khan Academy. While the claim is a bit of a stretch,
especially when you need to delve below surface level, they do have over 3,300 videos on everything from math to
physics, finance, and history. According to their website, in August 2004, Sal Khan began remotely tutoring his
cousin, Nadia, who was struggling with unit conversion. Soon, Sal also began tutoring her brothers as well. He
became so popular that he started recording videos and posting them on YouTube. More and more people kept
watching, and Sal has continued to make videos ever since. Khan eventually drew the attention of Google ($2
million grant) and Bill Gates ($1.5 million grant). The rest, as the saying goes, is history.
Cafe visitors might be particularly interested in subjects like circuit analysis (4 lessons), capacitance,
magnetism (12 lessons), electric motors, electrostatics, Doppler, optics, and fields. You might also like watching
the video lessons on momentum and torque, friction, gravity, thermodynamics (5 lessons), Newton's laws , and
fluids (12 parts).
For a little nerd fun watch the video on what the takeoff roll for an Airbus 380 would be for various
weights or how fast a baseball would need to leave the bat of a hitter at home plate to clear the Green Monster at
lessons do go well beyond introductory concepts by including vector products and calculus in the presentation.
Magnetism, for example, uses cross products in the high numbered lessons.
you need a math refresh, maybe the lessons on complex numbers would be helpful. If you're doing statistical
analysis, then the box-and-whisker lesson might help. There are modules for probability and statistics as well,
and for about a hundred other topics including trigonometry, geometry, factoring polynomials, exponents,
logarithms, linear algebra, and matrix operations.
Finally, if you are involved in the business side of the
company, lessons on microeconomics and macroeconomics cover topics like the business cycle, fiscal policy,
inflation and deflation, investment, and money supply.
Even if these video lessons are of no interest to
you, they might be just what your kid is studying in school. The fresh insight from a different instructor could
be just what he/she needs. It's worth a try.
The August 2012 edition of IEEE's
magazine ran an article on Khan Academy if you want more information (other than just visiting
These items are an archive of past Topical Smorgasbord items that have appeared on the RF Cafe homepage. In keeping with
the "cafe" genre, these tidbits of information are truly a smorgasbord of topics. They all pertain to topics
that are related to the general engineering and science theme of RF Cafe.
Please send me an e-mail
if you have
a good subject.