Recent content by jbriggs444

On the contrary, I would expect an effect for all circle sizes. The effect would gradually increase as the diameter of the circle increases toward a great circle. [Depending on exactly what one holds constant as the circle diameter is increased] Let us think in terms of the fictitious...

[Water] siphons stop working at about 0 C.

Which would mean that no water is exiting at the bottom.

If the water level is constant then the surface water is motionless. If it is supposed to be raining, then one needs to say so. The people making up these questions need to invest in some proof readers.

I dislike this question. It is full of ambiguities. It appears that by "at maximum height" they mean the maximum height to which the top of the siphon could have been adjusted. At that height the [absolute] pressure in the fluid would be zero. Any higher and the fluid would spontaneously...

As I understand things... Definition: two clocks are said to be "synchronized" if their readings when located at simultaneous events are equal. Conversely, for synchronized clocks, their readings can only be identical if the clocks are located at a pair of simultaneous events. Obviously, the...

Yes, that passage is apt. An absolute bearing (or heading or course) would typically use a 360 degree rosette as described above with 0 to the north, 90 to the east, 180 to the south and 270 to the west. One can also use relative directions. e.g. "Where does she bear?" "Two points off the port...

What about literature from Edward Everett Horton?

I suspect that the intended meaning mean that the fly is flying on a heading of 204 in still air. "Bearing" is the direction from a reference point to a particular object. e.g. Which way from the fly to the sun? "Heading" is the aiming direction of a moving object. e.g. Which direction is the...

I would say that nothing physical needs to change its state of motion. It is just coordinate systems. Scribbles on pieces of paper. This part of the coordinate system over here right now is moving differently from that part of the coordinate system over there back then. [There can be...

Yes. I agree with pretty much everything you have written about the distinction between real and fictitious forces. A real force (or "interaction force") is one that has a third law partner. A fictitious force will (in almost every case(*)) not have a third law partner. Here I disagree...

Anyone with eyes that function underwater and using stereoscopic binocular vision for distance detection will correctly determine underwater distances. It is simple triangulation irrespective of how one brings the two images into focus. I agree with @.Scott about the manner in which being...

Here in the U.S. the number of days per school year is set by state law. The local school districts are then free to schedule the school year in accordance with that restriction. Political pressure for low taxes and low spending then has the effect that local school districts schedule exactly...

What is the stroke distance? That is, what is the height difference between the piston at the bottom of a stroke and the piston at the top? From the drawings, it looks like about 0.1 meters. That means that you will be drawing up about 1 meter2 times 0.1 meters = 0.1 m3 of water with each...

Yes. I think that everyone here understands that. You want the total of: 1. The force of water pressure on the bottom surface of the top piston ##F_{3bt}## plus... 2. The force of water pressure on the top surface of the bottom piston ##F_{3tb}## plus... 3. The force of water pressure on the...