Recent content by xatu

Thanks a ton, I got it now! Interesting way of looking at things!

Yes, but I don't exactly understand how the angle between the y-axis and ##r##, and the angle ##\theta## being complementary to one another tells us anything about the angle between ##M_O## and ##M_y##. I get that the angles adjacent to ##\theta## are equivalent to ##90-\theta##, but, to me...

##M_O## is, by definition, perpendicular to the plane containing ##F## and ##r##. The angle between ##M_O## and ##r## is thus 90°.

##M_O## is the moment of the force ##F## about the axis through point O.

Homework Statement In my statics book (13th ed. Hibbeler) I'm reviewing the section about using vector analysis to calculate the moment of a force about a specific axis. I understand the theory fine, but I don't completely understand the figure in the book (pic attached). Specifically, why are...

I had the following thought when thinking about this lately: Would a connecting wire in a circuit even have a voltage across it? Conducting wires have practically no resistance, and, by Ohm's Law (V=iR), have V≈0 for any i?

Thanks for the insightful reply vanhees! Very helpful!

Figured I'd reach out here to see if anyone had recommendations.

Not sure if I posted this in the correct area, but hopefully it will be moved if I haven't done so. I'm here asking you guys if you know any books relevant to writing a paper on the subject of "The Development of Newton's mechanistic Universe - Principia (1687)." It's for a history class, so...

Thanks for the help guys. So basically it seems that our concern with node voltages is somewhat arbitrary, mainly owing to its ease of measurement. Right?

Question: When we discuss voltages in a circuit, why are we particularly interested in the voltages at nodes? For example, Kirchoff's Voltage Law states that the sum of the voltages around in closed circuit is 0. This implies that every source/load voltage in a circuit is located between two or...

Indeed Jackson's book is listed as an optional book. The required text is Griffith's. http://www.astro.caltech.edu/~golwala/ph106bc/#mozTocId238853 Well said WannbeNewton.

It's easy to fool oneself into thinking that you understand something - especially in self-study. I advise that you actively read through the chapter of whatever book you are working (with pencil and paper) until you fully understand and are capable of deriving the key results. Once you've...

Hi, welome to PF! Woah that's GR, you have a long (but fun) way to go! I'll just recommend some starters, I'm sure others will chime in. Most people on here will say that Halliday & Resnick problem are far too easy (especially the newer editions). Since you say you are familiar with calculus...

Look at how the quantities are related in Snell's Law: (ie. n_1sin(θ_1) = n_2sin(θ_2)) If n_2 gets larger, then θ_2 gets smaller. If n_2 gets smaller, then θ_2 gets larger. So from the angle of the refracted ray, you are able to reason out the relative indices of refraction.