Archived threads in /sci/ - Science & Math - 446. page
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hey, /sci/, i have a question about the otto cycle (applied thermodynamics exam soon). If it is symplified like pic related, is the work done by any single transformation int(pdv) or -int(vdp)? The total work in both cases is equal (same area on p-v diagram). I know that -vdp is for flows through an open system, and a typical cylinder IS an open system, but at the same time there is moving boundary work and you can't realy use a control volume. Help pls
>>7788196
pls respond
>>7788274
an ideal otto cycle, is asummed to be a closed system, because the energy transfer happens in a fixed mass or control mass. then, by the enthalpy definition, dh=du + pdv + vdp, but the latter terms become zero, because is a closed system. given this, using first law, and having in mind that the expansion and compression are adiabatical processes (q=0), then the work is defined by means of the internal energy changes. hope this helps.
>>7788378
I always thought this was called the Carnot cycle, but yes this anon is right. Also, the entropy for the system will be 0, which I'm sure you'll learn soon.
>tfw spend hours to wrap my head around a concept from different sources
>I could teach it to myself in 1/10th of the time
>>7788159
>Can't understand when it is being dumbed down so that even a retard 5 year old could get it.
>Thinks he could do it on his own without any hand holding
Oh man, brainlets. Am I right?
>>7788170
what
>>7788170
oh I understand now what you mean.
no I mean if I could go back in time I could teach it my past self in 1/10th of the time after I studied it
Why does pain stop us from doing things?
Why is it a *must* that we survive? What is the final purpose of reproduction?
pain indicates that body is recieving damage, and as a survival defense mechanism it pushes you away from the thing that hurts you.
>>7788135
Pain is pleasure
>>7788135
>Why is it a *must* that we survive?
It's not. In fact one day you will stop doing it.
>What is the final purpose of reproduction?
Nature doesn't have purposes. It doesn't have a mind.
how come force moves things?
>>7788095
The midichlorians from a system interact with the midichlorians of another one, indicating them how to react.
Because force is an acceleration which is a change in momentum. Changing the momentum of something usualy tends to move it in space.
>>7788111
so... newtons F=ma is actually F=a?
Any medical students here? Any premeds? How's life as a medical student? Share your story if you were ever interested in getting into medicine.
>>7788091
Pre-med is basically a bio major. The physics and math in pre-med is so simple that it's only half of what A-level covers
>>7788101
How difficult is a bachelors in engineering really? I'm hoping to get into med school but I don't want to be completey unemployable should I get rejected.
>>7788106
Just no life the Pre-med you should be fine, don't drink, don't party until you get into the safety net, which is med school
Retard code monkey here.
I'm trying to find out how to create an algebraic function which would input the number of items a search query returned, and output the number of pages, given that X items per page are allowed. How do I do this?
I know how to do that using set builder notation, but this isn't what I need in this practical world.
ceil(number of items/X)
>>7788053
num_pg = 1 + ((items - 1) / X);
What is the general way of finding the integers of this type?
Thanks
>>7788043
>integers
fuck me, meant integrals
https://en.wikipedia.org/wiki/Partial_fraction_decomposition
Pleas learn \latex
How is it that it's 2016 and we still don't have a definitive answer as to what happens after we die?
you die. nothing else happens
But we do know what happens: your body decomposes and the molecules that made you are now being used in other things. Oh you mean what happens to "your consciousness"? Turns out it's just an emerging phenomena that happens when enough neurons connect in a certain way that allows for massive parallel processing of information and this process is allowed to run for several million years of iterations.
What happens??
>>7788006
I1=I2=0
Either
a) The middle of the write has the lowest potential
b) Particle collisions
>>7788006
Depends on how the impedances are matched. Probably waves happen
Can any psychologists explain this to me?
It seems as if what is and isn't a mental illness changes all the time in accordance to popular opinion. For example, in the 60s being homosexual was a mental illness, but now it isn't. Why is feeling sad a mental illness but wanting to change gender isn't? Or wanting to have sex with children and wanting to have sex with other men. This makes psychology feel very disingenuous as a science.
>>7787854
Xenoestrogens, increased amount in ecosystem, increased amount in our food, increased amount in our bodies and a long duration of them being used.
>>7787854
>Why is feeling sad a mental illness but wanting to change gender isn't?
But it is:
>https://en.wikipedia.org/wiki/Gender_dysphoria
>GID is classified as a medical disorder by the ICD-10 CM[7] and DSM-5 (called gender dysphoria).[8]
>>7787866
So why are transgender people supported and not put on medication?
Amsart or article? Which do you prefer?
>>7787851
Amsart.
Is this even a question?
>>7787851
>Amsart
>KKKHHHHHAAAAANNNNN!
/thread
If mathematicians are so smart, why do they believe in god? A rigorous scientific education should expunge the belief in fantastical deities, not strengthen it.
Pretty sure there are atheist mathematicians out there.
>>7787836
only very dumb people believe in god blindly.
only smart people realize deep inside that god in fact exists.
>>7787841
This basically. There are blind people throughout most religions and non-religions. Intellectuals believe that God exists from a philosophical viewpoint. The mindless ones follow it due to socialization and see it as an answer to all of the questions they're too lazy to reason through themselves.
Can rapamycin be used to treat cancer and more?
Can it be synthesized?
>>7787803
>Can it be synthesized?
Nicolaou did it in '93 so yes.
Is this statement scientifically accurate?
Upvoted :^)
>>7787793
No you fucking fag, humans aren't light bulbs.
>>7787793
>Knows it is joke
>Asperger mind still making me correct
The light bouncing off of them into your eyes has no connection with their intellect. So no.
What is the most prestige faculty in your university? Not really just in terms of money, fame or easy access to jobs afterwards but also what is considered around the campus to be exceptionally difficult and/or demanding and/or most difficult to be accepted ?
I've started this semester to learn Physics and Electrical Engineering. In my campus it's considered top next to Medicine.
(also, apologizing if my English is somewhat broken. not 1st language and whatnot.. )
pic somewhat related - it differs around the world.
Most difficult to get accepted:
U of T: Engineering Science
McMaster: Health Science
Waterloo: Math/Chartered Accounting
I'm not sure if other schools really have programs that are notoriously difficult to get accepted to.
Why is this important to you?
>>7787764
U of T PHd in medicine is notoriously difficult to get into.
