140,605 reputation
9242395
bio website ratsauce.co.uk
location Chester, United Kingdom
age 54
visits member for 4 years, 5 months
seen 40 mins ago

Semi retired old time computer nerd who started programming on a Commodore Pet.

Since I'm also active in the Physics forum I should add that I started as a theoretical chemist, moved into solid state photochemistry and finally worked in industry as a colloid scientist. I only became a full time computer nerd in 1997.


Jun
24
comment Electric DC circuit: bridge type circuit using Thevinin analysis
Hi Palu and welcome to the Physics SE! Please note that this is not a homework help site. Please see this Meta post on asking homework questions and this Meta post for "check my work" problems.
Jun
24
comment Why dont we consider force exerted by atmospheric pressure in mechanics?
Related, and possibly a duplicate: A book sits on a table. What is the net force of air pressure?
Jun
24
comment How any trajectory can be linear?
+1 Indeed you could do it, and indeed General Relativity does do it.
Jun
24
comment Does Ice made with hot water melt faster than ice made with cold water?
I don't think this answers the question. The first part of your answers discusses the Mpemba effect, which the OP didn't ask for and which they already know about. The second part of your question just says melting is unaffected, without giving any justification or evidence for the claim.
Jun
24
comment Does Ice made with hot water melt faster than ice made with cold water?
It is entirely possible. For example ice made from water that has been heated will have much less dissolved air in it that ice made from water kept at a low temperature. Whether this has any effect on melting I don't know, but it seems a possibility. If the water is hard then boiling will reduce its ionic strength, and that again may have an effect.
Jun
24
comment To find the acceleration with which ring starts moving if the system is released from rest in terms of initial angle Ө?
Hi and welcome to the Physics SE! Please note that this is not a homework help site. Please see this Meta post on asking homework questions and this Meta post for "check my work" problems.
Jun
24
comment What is the radius of the event horizon?
Anyone interested in this may want to look at Anonymous' previous question on the subject as my answer to that provides more detail on what the metric tells us.
Jun
24
comment How to derive the Schwarzschild radius?
I've closed this as a duplicate of the new question, since the answers to the new question cover this one as well.
Jun
24
comment Questions on Ruhmkorff coils
This is a bit off-topic here, though it would be ideal for the Electronics Stack exchange.
Jun
24
comment How to derive the Schwarzschild radius?
@Anonymous: that's too big a question to answer in a comment. You might want to post it as a new question.
Jun
23
comment Two Hexagon Grid System Equivalent Resistance
Hi Sanchayan. Please note that this is not a homework help site. Please see this Meta post on asking homework questions and this Meta post for "check my work" problems. I realise this isn't actually homework, but it falls into the same category.
Jun
23
comment How to derive the Schwarzschild radius?
@Anonymous: Chris White is quite correct to pick me up for being loose with my argument. Defining exactly what the event horizon is turns out to be a lot more complicated than I've made it sound. However, in this case the Schwarzschild radius is indeed the distance where the coordinate singularity occurs.
Jun
23
comment Why Owl wins and aircraft loses in the competition of silence?
An owl is quieter because it isn't powered by a jet engine. I honestly don't see how this question can be usefully answered. If you wanted to ask what is the origin of the noise a jet engine makes? that might be a better question. Or I suppose how does the noise from a glider compare to the noise from an owl? However I doubt people would be queuing up to answer either.
Jun
23
comment Why Owl wins and aircraft loses in the competition of silence?
Can you clarify what you are asking? You appear to be asking why a jet plane makes more noise than an owl, and if so this is not a very deep question.
Jun
23
comment Terminal velocity of a steel ball in water
@Kejia1026: $C_d$ has to be measured experimentally. The values of Cd for a sphere in water are almost certainly available somewhere in Googlespace.
Jun
23
comment Can pre-inflationary gravitational attraction affect objects after inflation?
A footnote: I couldn't find a good article on the Hubble drag. Wikipedia doesn't have an article on it and the only articles I found were rather technical. If anyone knows of a good article on the Hubble drag please feel free to edit my answer to include the link.
Jun
23
comment Terminal velocity of a steel ball in water
Strictly speaking $A$ is the reference area, which for a sphere is the frontal/cross section area (the two are the same for a sphere).
Jun
22
comment What is the difference between real orbital & complex orbital?
Closely related, and maybe even a duplicate: What is the difference between the phase in molecular orbitals and the actual complex phase component of the wave function?
Jun
22
comment What is the space-time curvature angle that produces a newton of force?
If you're interested in how to calculate the acceleration caused by the curvature of spacetime we can describe how it's done. However it's a (very!) complicated calculation and isn't described by just an angle. As it stands I'm afraid your question doesn't make any sense.
Jun
22
comment Mathematical expression of energy storage
The bending energy of the surface would normally be related to the principal curvatures. I confess I'm not sure how these are related to the Riemann tensor.