Recent content by Zheng_

The equation of flow acceleration is where du/dt is the global acceleration, and ∂u/∂t and u ∂u/∂x are local and convective acceleration respectively. And the heat conduction equation is which is heat stored = net heat flux + heat generated. My question is: why does the ∂T/∂t part in the...

Homework Statement I was learning how to calculate moment of inertia on Youtube, and I'm confused about when to use 1/2 mr2 instead of mr2. This video says that he used 1/2 mr2 instead of mr2 because the cone is solid But in this video, while he was calculating a solid sphere, he used mr2...

If two gears are joined to together, how are their moment of inertia calculated? Separately or combined?

Homework Statement By the data given below, Condenser Inlet Pressure (P1/kPa) 1164 Condenser Inlet Temperature (T1/K) 382.8 Condenser Outlet Pressure (P2/kPa) 1102 Condenser Outlet Temperature (T2/K) 297.2 Evaporator Inlet Pressure (P3/kPa) 290 Evaporator Inlet Temperature (T3/K) 259.5...

Also, the question I'm trying to ask is "if a with respect to b, which is the independent variable? R Also, if a with respect to b, which one is the independent variable? Reference https://www.physicsforums.com/threads/if-a-with-respect-to-b-which-is-the-independent-variable.896384/

But if it is a T-v diagram, doesn't it means that v must be the independent variable(x-axis)?

Ok. Thanks for the help!

Something like this

Homework Statement My lecture note says that "T-v diagram shows change in specific volume of a substance with respect to temperature.". Is it correct? Homework EquationsThe Attempt at a Solution If a(Specific Volume) "with respect" to b(Temperature), then b(Temperature) should be the...

Homework Statement If A has a mass of 300kg, determine the mass of B if the system in figure P4-28 is to be in balance. (What I couldn't understand is the 2Tb in the answer.) Homework Equations ΣFy=0[/B]The Attempt at a Solution Since the pulley on top is connected with two pulley at the...

Homework Statement The wall shown in Fig. 4.28 is 20 ft long. Calculate the total force on the wall due to water pressure and locate the center of pressure Homework Equations Are resultant force and total force the same? The Attempt at a Solution I think they are not the same because resultant...

Ok thanks. I will go and read through my textbook.

But..one of the question in my homework let that I rms = 2∠10°?

Ok thanks

What I'm asking is RMS currect. I know that voltage and currect in AC circuit can be phasor, but why RMS current, which descibe a effective value, can be a phasor? It wouldn't change its value as the time is passing right?