Help with a thermodynamics problem, calculate energy transfer?

[kawf]

Homework Statement

A mass of 5 kg of steam is contained within a piston cylinder assembly. The steam undergoes an expansion from its initial state with e1 = 3000 kJ/kg to its final state with e2 = 2500 kJ/kg. During the process there is a heat transfer of 80 kJ to the steam. Also, a paddle wheel transfers 10 kJ of work to the steam. Calculate the amount of energy transfer by work from the steam on the piston during the process.

Homework Equations

dE = del Q - del W

The Attempt at a Solution

Would this be correct?
W = del Q - dE
= (80kJ + 10kJ) - (2500 kJ/kg - 3000 kJ/kg)
W = 590 kJ

I don't believe this is correct but it's all I have been able to come up with so far. Any guidance is appreciated

 

[freezard7734]

I believe you should be solving for delQ

 

[Blueshift5]

.

I would approach this problem by first understanding the concept of energy transfer in thermodynamics. The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. In this case, we have a closed system (the piston-cylinder assembly) and we are given the initial and final internal energy values (e1 and e2) as well as the heat transfer and work done by the system.

To calculate the energy transfer by work from the steam on the piston, we can use the first law of thermodynamics:

dE = del Q - del W

Where dE is the change in internal energy, del Q is the heat added to the system, and del W is the work done by the system.

Plugging in the values given in the problem, we have:

dE = (80 kJ) - (10 kJ)
= 70 kJ

Therefore, the energy transfer by work from the steam on the piston during the process is 70 kJ. This means that the steam has done 70 kJ of work on the piston during its expansion.