Recent content by imnotadmin

Sorry I put a wrong data in the first thread. The diameter of the vessel is 100mm and the thickness is 0.55 mm. The r/t = 90. I have checked a textbook and it mentioned " when r/t =10, the results of a thin-wall analysis will predict a stress that is approximately 4%. For larger r/t, this error...

pls help-- thin-walled pressure vessel Hi, all. I have done an experiment of “thin-walled pressure vessel”. The vessel: length 200mm, outside radius 526mm, inner radius 47.6mm. There were two rectangle rosettes gauge in the vessel surface. Based on the experiment data (100 psi), the actual...

Thank you!

yes! got it thanks very much to all

sorry, i don't know what u meant adiabatic process delta U=Q+W, and Q=0 => delta U=W isothermal process delta U=0 so if a process is adiabatic and isothermal, when the work done by system or at system, it is impossible to satisfy U=W and U=0

adiabatic process delta U=Q+W, and Q=0 => delta U=W isothermal process delta U=Q+W, and delta U=0, => Q=-W combine these two factors, so conclusion is impossible a process adiabatic and isothermal. Right?

so? still confuesd...

thanks. when a system is doing an adiabatic process, there is no heat can trasfer from or to outside. so the total energy of this system must be changed.

thanks. I am not sure that I understand completely what u said. But I think u mean that there is impossible a process is both adiabatic and isothermal. That is because when outside environment doing work to the system, the internal energy must be changed. And work can be change to heat 100% but...

Homework Statement Is it possible to have a process that is both adiabatic and isothermal. Homework Equations The Attempt at a Solution I think the answer is no. Because when a system is doing an adiabatic process, the total energy of this system must be changed. For an...