The Efficiency of Heat Engines: Calculating Work Output from 150J Heat Input

  • Thread starter Thread starter Dx
  • Start date Start date
  • Tags Tags
    Efficiency Heat
Click For Summary

Homework Help Overview

The discussion revolves around the efficiency of heat engines, specifically calculating the work output based on a given heat input of 150J and an efficiency of 35%. Participants are exploring the relationship between heat input and work output in the context of thermodynamics.

Discussion Character

  • Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to calculate work output using the formula for efficiency but expresses uncertainty about the correctness of their calculation. Other participants inquire about the definition of efficiency and discuss the possibility of errors in the original poster's understanding or the source material.

Discussion Status

Participants are engaged in clarifying the definition of efficiency and verifying calculations. There is a recognition of differing interpretations of the problem, but no explicit consensus has been reached regarding the correct approach or answer.

Contextual Notes

There is a suggestion that the original poster may have misunderstood the problem or the definitions involved. The discussion reflects a need for clarity on the definitions and calculations related to heat engines and efficiency.

Dx
A heat engine has efficiency of 35% and receives 150J heat per cycle. how much work dos it perfrom in each cycle?

I said 52.5J

w=e*q_h =
.35 * 150 =
52.5
its wrong

what did i do wrong with this calculation. unless it mean 150J of put in. can anyone please explain this to me.
TY!
dx :wink:
 
Physics news on Phys.org
Can you post the definition of efficiency from your book?
 
efficiency(e) = W(work out) / Q_H(work in)
 
Originally posted by Dx
efficiency(e) = W(work out) / Q_H(work in)

That's what I thought. OK, just plug-n-chug.

(You know, it's always possible that the book is wrong!)
 
Originally posted by Dx
A heat engine has efficiency of 35% and receives 150J heat per cycle. how much work dos it perfrom in each cycle?

I said 52.5J

w=e*q_h =
.35 * 150 =
52.5

I thought i did that like shown but aparently its not right. I just wanted to know does your answer match mine?
Dx:wink:
 
Yes, it does.
 

Similar threads

Efficiency of Stirling Cycle - Is it the same as the Carnot Engine?
  • · Replies 14 ·
Replies
14
Views
3K
Thermodynamics Problem: Calculate the heat input for this work output
  • · Replies 17 ·
Replies
17
Views
4K
Calculating the Efficiency of a Heat engine
  • · Replies 32 ·
2
Replies
32
Views
5K
Thermodynamic Cycle -- Work done as a function of Heat absorbed
  • · Replies 3 ·
Replies
3
Views
2K
Obtaining work from two bodies by a heat engine
  • · Replies 2 ·
Replies
2
Views
3K
High School Heat pump as a heat engine that operates in reverse
  • · Replies 19 ·
Replies
19
Views
5K
Thermal efficiency of a heat engine
  • · Replies 3 ·
Replies
3
Views
2K
Heat Extracted and Delivered to Reservoirs in a Heat Engine
  • · Replies 7 ·
Replies
7
Views
3K
Efficiency of a Simple 3-Stage Ideal Gas Cycle: Analyzing Thermal Efficiency η
  • · Replies 3 ·
Replies
3
Views
3K
Work done by a 20% efficient heat engine
  • · Replies 23 ·
Replies
23
Views
5K