What is the efficiency of the engine?

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Discussion Overview

The discussion revolves around calculating the efficiency of an engine based on the work done to lift a load. Participants are examining the numerical values and equations involved in determining efficiency, focusing on the relationship between work done and work required.

Discussion Character

  • Technical explanation, Debate/contested, Homework-related, Mathematical reasoning

Main Points Raised

  • One participant proposes that the efficiency can be calculated as 400/50,000, leading to a conclusion of 8% efficiency.
  • Another participant questions the validity of the numbers used, specifically the values of 50,000 and 400, indicating confusion over their origins.
  • A different participant calculates the work done as approximately 400 joules using the formula 10kg * 9.8N/kg * 4m.
  • Concerns are raised about the correctness of the 400 joules value, with a suggestion to clarify the numerical value used.
  • One participant expresses uncertainty about their calculations, stating they arrived at a value of 24.5 but is unsure about the second line of their work.
  • There is a call for participants to show their work and provide clear equations before substituting values.

Areas of Agreement / Disagreement

Participants do not appear to agree on the numerical values or the calculations presented. Multiple competing views and uncertainties remain regarding the correct approach to determining efficiency.

Contextual Notes

There are unresolved issues regarding the assumptions behind the numerical values used and the definitions of work and efficiency. Some calculations appear to depend on unclear or incorrect assumptions.

Who May Find This Useful

This discussion may be useful for students or individuals interested in understanding the calculations involved in determining engine efficiency, particularly in the context of physics problems related to work and energy.

bluemoon
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f an engine must do 500 joules of work to pull a 10 kg load up to a height of 4 meters, what is the efficiency of the engine?

So that's
400/50,000

which gives me 0.008

Does that mean the efficiency is 8%?
 
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where did you get your numbers from?

50k?

400?

None of this makes any sense.
 
Work done: 10kg*9.8N/kg*4=appx 400J

efficience= work done/500 * 100
 
400J is not correct, please write down the correct numerical value.

Your second line is not correct.

efficiency = work needed ideal/ work actually required

It is always less than one.
 
Okay for my first line, I got 24.5

and I don't know how I'm messing up on my second line. ??
 
where are you getting these number from?

You need to start showing me your work and not just some random numbers you are calling approximations.
 
Bluemoon : Please write down the equations before plugging in numbers.
 
Last edited:

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