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
AI Thread Summary
The discussion revolves around calculating the work output of a heat engine with an efficiency of 35% and a heat input of 150J. The initial calculation of 52.5J for work output is presented but questioned for accuracy. Participants confirm the formula for efficiency as work output divided by heat input, leading to the same result of 52.5J. There is some confusion about whether the calculation is correct, but it is ultimately validated by another participant. The consensus indicates that the calculation method is sound, despite initial doubts.
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.
 
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanged mass'

Thread 'A cylinder connected to a hanged mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Efficiency of Stirling Cycle - Is it the same as the Carnot Engine?
Replies
14
Views
1K
Thermodynamics Problem: Calculate the heat input for this work output
Replies
17
Views
4K
Calculating the Efficiency of a Heat engine
Replies
32
Views
4K
Thermodynamic Cycle -- Work done as a function of Heat absorbed
Replies
3
Views
2K
Obtaining work from two bodies by a heat engine
Replies
2
Views
2K
B Heat pump as a heat engine that operates in reverse
Replies
19
Views
4K
Thermal efficiency of a heat engine
Replies
3
Views
2K
Heat Extracted and Delivered to Reservoirs in a Heat Engine
Replies
7
Views
2K
Efficiency of a Simple 3-Stage Ideal Gas Cycle: Analyzing Thermal Efficiency η
Replies
3
Views
2K
Work done by a 20% efficient heat engine
Replies
23
Views
4K

Hot Threads

Recent Insights

Back
Top