Recent content by jbriggs444

Not a problem at all. Language issues are no one's fault. As I use the words, the force assignments are: "Normal force": The perpendicular (upward in this case) component of the contact force of a flat surface on an object in contact with that surface. You appear to call this "normal reaction...

I want to be very sure that I understand what you are saying. You have tossed out three terms here: "weight" "gravity" "normal reaction" You've already indicated that "weight", for you, is a synonym for the normal up-force of surface on body. The "normal reaction" would then be the third law...

As has been suggested, create a free body diagram and apply Newton's second law.

Try to be precise. Exactly what do you mean by "weight"? A) The force of Newtonian gravity from the Earth on the body? ##W=G\frac{mM_e}{r^2}## B) The support force supplied by the scale on which the body rests? ##W=F_n## C) The down-force from the body on the surface? ##W=-F_n## D) The...

A graph of cumulative distance versus time is not the same as a graph of speed versus time.

Why an ellipsoid rather than an ellipse? Shallow water waves propagate in two dimensions, not three. You have to use shallow water waves because deep water waves do not have a fixed propagation speed. Compression waves are ridiculous for this purpose.

Using this post as a test bed. [Chrome Version 124.0.6367.207 (Official Build) (64-bit)] I insert some in-line ##\LaTeX##: ##\frac{1}{\sqrt{1-v^2/c^2}}##. The raw text is: ##\frac{1}{\sqrt{1-v^2/c^2}}## Press preview (and refresh the page to get MathJax rendering). Looks good so far. You can...

Yes. The centripetal component of the resultant force varies with the velocity speed.

Well yes. The force of the object on the scale is an interaction force. Every interaction force is part of a third law pair.

I look at it differently. The laboratory frame need not be inertial. As you point out, one then needs to introduce inertial forces to obtain the second law force balance. In a rotating space station, one can then confidently step on a bathroom scale and judge that the apparent centrifugal...

Newton's second law. And Newton's third law. One assumes that the object in question is at rest in the chosen laboratory frame. According to Newton's second law, this means that the net external force on the object is zero. The only two forces on the object are the force from the surface/rope...

Speed can change during circular motion around a horizontal axis. But it need not do so. Consider, for example, a bug of negligible mass clinging to the side of a rotating wheel. If the wheel rotates at a uniform rate, the bug will travel in uniform circular motion. If you complain that the...

"Having" a dimension is not the same as "being" a dimension. The meter ("m") has the dimension of length ("L"). See the table here. Unless one is trying to chop word salad, I regard such fine points as being of limited utility. You can use the language to pass a test but it won't help much when...

The doppler shift depends on whether the source and receiver are approaching or receding. Doppler corresponds to the change in signal delay from one perceived pendulum swing to the next. But the expected interpretation of "measure" in this problem is one where Mo has already cancelled out...

It is flatly wrong. It assumes a framework of absolute simultaneity -- that everything that happens does so at a particular knowable time. Or, at least, it makes the erroneous assumption that specifying an observer is enough to take the ambiguity out of the notion of the time at which remote...