Recent content by sophiecentaur

II that 'cheap' like a second hand Maserati or cheap cheap? Captain Ahab went overboard , remember so be careful. I guess they need all you existing gear to do their stuff. I'm pleased for you and the images are interesting. Could you do labels? :thumbup:

The guys doing the job don't seem to be working efficiently. Was there any staff training involved? They seem to be splashing water everywhere with no particular end in view. It's the same problem that you get trying to get rid of sand from a shower tray; it just won't do what it's told. But...

Surely the whole problem should be considered. The bowl will absorb heat and lose heat in proportions that correspond to the temperatures all around the bowl. If the bowl is in an ambient temperature just above 0C then it won't freeze. Are you intending to keep the bunnies from freezing too...

.. . .. .. and 100 pounds on his foot or waist to push / pull them up. Easy to forget. No paradox if you include all the forces.

It's got to be complicated because the only wave that will pass the wire at c would be a plane wave, incident or launched along the axis of the wire. A wave, normal to the wire would have infinite velocity (breakers on a beach). So I think that implies there must be a number of near field waves...

A failure can be disastrous in a pneumatic system because of the stored energy in the gas. There are tales of charged diving bottles exploding in a car accident. Drive carefully to a dive site!

Here we go again, people (not you) want to apply a 'rule' when it's not actually relevant. The apparent speed of the waves along the wire can be anything when a plane wave arrives off-axis. It happens with sea waves breaking on a beach. The group velocity along a long wire antenna can be...

Words are at the centre of creating any mathematical model. Also, the correct words are important (basis of language). This whole thread is about a problem that involves the observer's empathy with the participant - 'what would I experience if I was the fireman?' Those sorts of problems can...

That's a relief @Filip Larsen , I couldn't believe PF never used it but I never bumped into it. I don't really like the term VR much because it assumes motion but I'm sure that many people are unaware of it as a real thing with real values. I mentioned above the idea of using a tree branch and...

I love to watch dredgers dumping silt out of the hull by opening doors in the bottom. Very elegant to let gravity do the work. The ship slowly rises up out of the water.

Fair enough but “gearing” is only a part of it and so would pulleys and levers, which have dead weight and friction built in. VR is an actual variable with a value. MA, likewise has a value and is the one which counts in real machines. Even in the simple example in the OP, friction in the pulley...

We are, of course, basically in agreement about the Physics. However, my experience is that, in mechanics threads the only term that I read is Mechanical Advantage and it is used very often, inappropriately. I'd actually claim never to have read the term "velocity ratio" in threads about...

I read in several articles (just google it) that sputnik1, at a distance of over 500km was not visible to the naked eye but, with the help of a radio receiver, could be found with binoculars. Sputnik 2 was a bit bigger and had a dog on board - same visibility. For those of a sensitive...

OH? It was tiny but the satelloon was huge. Did you yourself see Sputnik? I wonder what the viewing figures were. 65 years ago the light pollution may have been less but I remember seeing it with no trouble. I may need to alter my statement to include the words "many many viewers in the...

This belief persisted even to 1960 and beyond. In that year, the US launched a satellite which was a simple balloon and which stayed up in orbit for some while. I remember standing outside my grandad's cottage, along with my dad and we saw it ("the sateloon") go overhead. This was the very first...