Wonderful question, as it is translated from my native tongue, I will try and give some examples and explain a bit. Case refers to a problem in society which has been or can be fixed and then that particular solution. Where pointing to a problem which involves solutions from all 4 courses is the...
Hello physics forums I am newly started teacher at end high school level.
I am looking for ideas for a case which involves a course called technology, where the students learn how to create a product + one of the following four courses: Physics, communication & IT, biotechnology and design...
Had some busy days, anyway if we consider the mass of the sattelite to be a 10x10x10 aluminium cube + the solar panels. We get a weight of 1.5 kg+(density of aluminium *1000 cm^3)=4.2 kg. This is probably a crude approximation, but at least it will be in the ball park.
The acceleration profile...
Well from googling around a bit and doing some calculations I found that one would need about 1.5 kg of solar sattelites which is not unacceptable.
Given the mission takes a year, and solar panels can produce 300 W/kg (https://en.wikipedia.org/wiki/Solar_panels_on_ spacecraft ) . This is given...
Alright, I did not expect demands of simple considerations, but thank you for enlightening me. When I said I didn't know a lot about the legislation I could perhaps have expanded that to sattelites in general, as it was a friend who asked if I could build such an engine.
$$...
Thank you for the answers. With regards to the should, I do not know a lot about sattelite orbit legislation, but I imagine there are some international rules so they do not collide. But what if I wanted to fly my sattelite to the moon and orbit that instead?
How large would the solar panels...
Would it be possible to build an approximately 10x10x10 cm ion-engine to put on a cube sattelite? I am a university student, so we have a lot of tools, but not a lot of money.
What do I need to consider and how much would it cost?
No the sharp points are not necessary. You make a good point, but polishing only ~75 nm is practicly impossible with the tools we have at the university. Some form of well controlled chemical etch might do the job. Reactive ions etching could work if I could coat the grooves with a thin layer of...
okay maybe I don't not make myself clear enough. I made a drawing of what has been done to the PMMA and what I want to do with it. Maybe it looks a
bit odd due to the imgur upload. We have some PMMA with structure in it and then I want these structures to shrink and I thought heating them in...
I made some structures in PMMA and now I would like to even them out a little bit. The structures are made with thermal imprint and are 150 nm deep and with a period of 300 nm, which is the smallest stamp we have at the university, I could of course make a new stamp, but that would take a lot of...
As the title says: Can cheese evaporate and in case which temperature?
Today I was eating a toast and this came to mind.
Looking at the internet in general didn't give a clear answer, but most people said it couldn't
First I guess all the water in the cheese will evaporate, and then act...
The divergence of J(r')=0 making the second term zero
leaving
\int \frac{r−r′}{|r−r′|^{3}} \bullet J(r') dv'
where the gradient of 1/|r-r'|
I thought of several solutions but I can't really pin down the right one.
1: Making it into a closed surface integral and J(r') somehow...
First of, thank you for the help.
Taking the gradient with respect to r' gives
\frac{r-r'}{|r-r'|^{3}}
Hence the integral becomes \int J(r')\bullet\frac{r-r'}{|r-r'|^{3}} dv'
I discussed your reply with a friend and I would like to know how one of the two in the equation below is...
1. Use equation for the magnetic vector potential in the case of specific current distribution and show by direct differentiation that ∇\bulletA=0
A(r)= µ_{0}/4\pi \int J(r')/|r-r'| dv'
Homework Equations
∇\times B(r)= µ0J(r)
The Attempt at a Solution
We know that: curl of...