Question about the 2nd law of thermodynamics (heat loss)

AI Thread Summary
In a closed system with an ideal gas and a movable piston, the first law of thermodynamics states that the heat added (dQ) equals the change in internal energy (dU) plus the work done (dW). The second law of thermodynamics indicates that while mechanical energy can be fully converted to heat, the reverse is not entirely possible. When heat is added to the cylinder at constant temperature, some energy is lost due to inefficiencies in the conversion process. Although heat energy can be converted to work, this cannot be achieved in a cyclic process without some energy loss. Thus, maintaining constant temperature while adding heat results in energy dissipation, highlighting the limitations of energy conversion in thermodynamic systems.
Shovon00000
Messages
3
Reaction score
0
Thread moved from the technical forums to the schoolwork forums
Assume that a closed system of cylindar filled with ideal gas consists of a movable piston.We know from the 1st law dQ=dU +dW.
According to the 2nd law mechanical energy can be totally converted into heat energy but heat energy cannot be converted completely into mechanical energy.The question is"If we give heat to the cylindar and keep the temperature constant how will some of the heat energy be lost ?(here dU=0,and we know dQ=dU+dW)
 
Physics news on Phys.org
You can completely convert heat energy to work. You just can't do it by operating the system in a cycle.
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »
Thread 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »
Thread 'A bead-mass oscillatory system problem'

Thread 'A bead-mass oscillatory system problem'

I can't figure out how to find the velocity of the particle at 37 degrees. Basically the bead moves with velocity towards right let's call it v1. The particle moves with some velocity v2. In frame of the bead, the particle is performing circular motion. So v of particle wrt bead would be perpendicular to the string. But how would I find the velocity of particle in ground frame? I tried using vectors to figure it out and the angle is coming out to be extremely long. One equation is by work...
View full post »

Similar threads

Entropy and the Helmholtz Free Energy of a Mass-Piston System
Replies
8
Views
2K
Chemistry Show that book levitation by absorption of heat violates 2nd law
Replies
13
Views
2K
How Does Newton's Law of Cooling Affect Heat Loss Calculations?
Replies
2
Views
2K
Thermodynamics Problem: Reversible and Irreversible Processes
Replies
1
Views
2K
How Does Volume Affect Internal Energy in Thermodynamics?
Replies
6
Views
2K
Thermodynamics: Internal Energy, Heat and Work Problem
Replies
1
Views
2K
What Happens to Kinetic Energy of the Piston in an Isothermal System?
Replies
21
Views
2K
Entropy and the Laws of Thermodynamics
Replies
3
Views
2K
Small issue regarding the wording of a thermodynamics question
Replies
3
Views
1K
I First law of thermodynamics -- two different expressions for dQ
Replies
23
Views
2K

Hot Threads

Recent Insights

Back
Top