Recent content by calculus_jy

"... and no chemical reaction. " why is that... H=U+PV \Delta H=T\Delta S+V \Delta p?

I would like to know if someone here can help sort out my confusion... It is easy to derive that dU=TdS-pdV (no particle exchange) Then enthalpy H=U+pV will imply dH=TdS+Vdp That means under a constant temperature (dT=0) and constant pressure (dp=0) situation dH=TdS>(=) dQ Why is it...

thank you so much. However i didnt find much in Landau, under which section will i find the mathematical derivation in your second reference by hall

I did a bit of work and this is what i got, can someone tell me if this is right and is there another way that will make this shorter!? \bold{L}\cdot\bold{L}=-\hbar^{2}(\epsilon_{ijk}r_{j}\nabla_{k})(\epsilon_{ilm}r_{m}\nabla_{m})...

The angular momentum operator is given by \bold{L}=\bold{r}\times-i\hbar \bold{\nabla}How do we compute \bold{L}\cdot \bold{L}=(\bold{r}\times-i\hbar \bold{\nabla})\cdot(\bold{r}\times-i\hbar \bold{\nabla})? so that we can get a relation of L^2 with the lapacian operator i found this in a...

This questions has been bothering me for quiet a while Does lim_{x\rightarrow \infty} f(x)=0 \Rightarrow lim_{x\rightarrow \infty} f'(x)=0 if so can you please post a proof because its giving me a headache. If not would it please be possible for you to give me a counter example. Many thanks

In proving the Ehrenfest Theorem This is the typical first line: \frac{d }{dt}<O> = \frac{\partial}{\partial t} <\psi|O|\psi> = <\dot{\psi}|O|\psi> + <\psi|O|\dot{\psi}>+<\psi|\dot{O}|\psi> My question is how can the exact differential \frac{d }{dt}<O> be changed the partial...

if you use p=m(t)*v(t) and use product rule in differentiation you will get it dm/dt

according to Newtons second law: \vec{F}=\frac{d\vec{p}}{dt}=m\frac{d\vec{v}}{dt}+\vec{v}\frac{dm}{dt}(1) ie force impelled on a body is equal to the rate of change of momentum however when we use calculus to derive rocket equation we get: m\frac{d\vec{v}}{dt}={\vec{v}_{gas\; relative \;to...

but is it not true that if Newton's first law is not satisified, we conclude that a force acts upon it ? and so how to really 'verify' first law??

atyy what do you mean by 'results match the "simple laws.' is it not true that if a body is not traveling in straight line, then the observer conclude that a force is acting on it... and doctorGreg if you measure acceleration you already assume that the acceleration is in respect to a preset...

since last time i post about the defiinition, i read up about it, how i am still a bit unclear after reading few more post about this topic : einstein: a set of frames which move without acceleration to one another and that the laws of physics hold in the simplest-is the a definition or that...

1) can the rocket frame acutally say they are experiencing force but no acceleration since there frame is at rest? such that net F>0 v=0?? 2) becuase rocket is acceleating frame, is the galilean transformation of u-v=U actually viable?? where u is velocity of gas relative to earth v velocity...

so what you are saying is that from rocket frame, F= constant, from Earth frame F is not constant?? then do they have to specifiy in question wheter they are from rocket frame or from the Earth frame? i am a bit confused...in addition, in the rocket frame the observer will conclude that the his...

recently i came across quesiton: a rocket car movves on str horz track. half of car mass is propellent, during run, propellent consumed at constant rate and ejected at constant nozzle velocity the answer says that force is constant but accel is increasing however i got a major question: by...