Work Energy Theorem and total work

[spectrum123]

Plz tell me
Which is correct form of Work Energy theorem
1. Total Work = Toatl change in Mechanical Energy(Potental + Kinetic)
2. Total Work + Potential Energy = Total Change in Kinetic Energy
3. Total Work = Total Change in Kinetic Energy (Mention in the textbooks)

Actually i am confused when i prove Bernoulli Theorem for fluid.
Some writers use Total Work done(Due to pressure) + Change in Potential Energy = Change in Kinetic Energy


I think the expression is this one

Total Work done(Due to pressure) = Total Change in Mechanical Energy(Potential Energy + Kinetic Energy)

 

[mfb]

It depends on the signs you use.
Total energy is conserved.

 

[e.chaniotakis]

If mechanical energy is conserved , then you have : T1+ V1 = T2+V2
(T: kinetic energy, V: potential energy)
It can be written as T2-T1=V1-V2=>DT=-DV
Thus the potential energy diminishes. The amount of change in the potential energy is the work done, which is finally converted in kinetic energy, thus increasing its value.