Also what industries would be most difficult to rebuild?

Working on a game where you could do just...

We colonize an Earth-like planet with 2 million people...]]>

Could work out the resistor with current x resistance but unsure with the other two]]>

Just wondering where the appropriate place to put CAD-related topics on this board would be.

To give some context, I was thinking about posting a question about advice on constructing a Francis-vane impeller, so it feels like it falls in the mechanical engineering section; yet it...

Where do CAD questions go?]]>

particle pass through a slit of width 0.200mm. the wavelength is 633nm. after it pass through the slit they spread out over a range of angles . use uncertainty principle to determine the min. range of angles.

heisenbergs uncertanty]]>

A solenoid has 500 turns per meter and cross-sectional area 4cm

Current through it is increasing at 100A/s and flows in a clockwise direction. There is a wire loop, concentric with the solenoid which sits outside the...

Field induced by solenoid]]>

I'm from Norway and I'm planning to go to university in England in 2016 to study theoretical physics, but I can't decide which ones to apply for. I have never been to England so I don't know the best places to live, how's studying in London for example? Which schools rank the highest in...

University in England to study theoretical physics]]>

There is no provision for measuring output current when the machine is welding.

I'm thinking of adding a shunt to either the work lead or the return lead.

I don't know what size and rating I need.

The input...

How to measure amperes with a constant current welder?]]>

When the particle of mass M/2 collides...

Collision involving blocks and pulley]]>

Light at speeds faster than the speed of light?]]>

]]>

As I understand it in general relativity the paths of light rays, given by null geodesics, are scale invariant.

Is that correct?

Now Maxwell's equations in flat Minkowski spacetime are also...

Are photon energies constant for any observers?]]>

Frequently Made Errors - Pseudo and Resultant Forces

...

Frequently Made Errors - Pseudo and Resultant Forces - Comments]]>

Scattering amplitude, link between quantum mechanics and QFT]]>

I have drawn a circuit below which causes confusion:...

Current requires a closed loop to flow in DC, not AC?]]>

To begin, i'm a 17 year old in High School in 11th grade in Northern New Jersey. To give a little background in my schooling life, just like pretty much everyone else I did great in all...

High Schooler confused for future career]]>

Of course that...

single photon double slit, reset detector after each impact]]>

Also are there any parallels that can be drawn with the ocw mit courses for the various topics...

Prerequisites to Mathematical methods Mary Boas]]>

Does the school I graduate from matter?]]>

I'm not sure how to turn reactance to a voltage level using an op-amp? ]]>

Why is is that when we look in a mirror we expect to see a reflection equally as bright as the real image, but when we stand in front of a cliff and clap our hands we don't hear an echo as loud as the original sound?

Difference between sound echo and mirror reflection]]>

This question may seem as an axiom to some. I also feel the same.

Prove:

##\forall x\forall y\ p(x,y)\Leftrightarrow\forall y\forall x\ p(x,y)##

##Assume\ \forall x\forall y\ p(x,y)##...

Question on quantifiers]]>

Dual spaces and the meaning of "Dual"]]>

First of all, I want to let you guys know that I'm quite new to the subject so please bear with me in case I'm asking a very basic question here. I have a struggle with the way the Age of the Universe is calculated by using Hubble's Law: V = H x D and I hope you guys could clear...

Something about calculating the Age of the Universe]]>

On the other hand, diamond has a diamond structure, which is a simple cubic lattice with 8 atoms in basis.

Now, diamond has optical modes in addition to acoustical, while Aluminium does not. What...

Optical phonons in fcc-lattice]]>

A gas cylinder contains 4x10^4 cm cubed of hydrogen at a pressure of 2.5x10^7 Pa and a temperature of 290 K.

The cylinder is used to foll balloons. Each balloon contains 7.24x10^3 cm cubed of hydrogen at a pressure of 1.85x10^5...

Ideal gas problem]]>

I would like to know if every single white or colored splotch in these photos is a galaxy, or do single/individual stars/suns manage to get mixed in there?

Thank you for your time....

Galaxy cluster photos]]>

Edit: Apparently the light on one of his power strips...

LED Bulb that Stays Lit Despite Power Outtage]]>

I'm looking at some logic diagrams for relays and have encountered something that I've never seen before. I haven't looked on the internet extensively since I thought the folks here at the forums would be able to answer my question more quickly. My experience with logic is...

Logic diagrams for relays help]]>

I have an engineering economics exam this week. I'd like to know if anybody (particularly professors and/or tutors) know of a website or have a document they could share with me with a few practice problems. I have attached a PDF document with the...

Engineering Economics - Practice Problems]]>

Profesor has 17 keys, and only one unlocks the door.

Let random variable X be attempt at which profesor unlocks the door (key that doesnt work is saved by side)

Find:

a) Most probable value of variable X

b) In which attempt...

conditional probability]]>

Now, think of the same thing from a different reference plane. Think of a still particle...

What is a magnetic field? (fun mental exercise)]]>

The solution is ##k=l(e^{ial}-1)/(e^{ial}+1)=il tan(al/2)##

FIRST QUESTION

So it's a quadratic in k, should be simple enough, my working so far using the quad. formula is ##k= (4l^{2}(e^{-ila}+e^{ila})\pm...

Tricky Quadratic formula / trig identities]]>

I understand how the...

Vacuum tubes and electronic oscillators]]>

This appeared in my news feed on the old Facebook, and my interest was piqued. Upon taking the quiz myself, I discovered a few noteworthy things.

First of all, to my surprise, I was reported to have missed one of...

Scientific Illiteracy article]]>

A question regarding transmission line]]>