Calculating Food Value of a Peanut Through Thermodynamics: Efficiency and Joules

In summary, the conversation discusses the calculation of the food value of a peanut burned under water. The equation q=mCt is used to calculate the energy given off by the peanut, with a 40% efficiency. The conversation also includes an analogy using apples to explain the concept of finding the total energy output.
  • #1
ashvuck101
27
0

Homework Statement



6. Cameron burns a 0.5g peanut beneath 75g of water, which increases in temperature from 22 ºC to 40 ºC
a. Assuming 40% efficiency, what is the food value, in J, of the peanut?
b. What is the food value in J per gram?

Homework Equations


q=mCt


The Attempt at a Solution



i just wanted to know does question a mean i take 40% from the calculated joules?
 
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  • #2
No, it's not, what it's saying to you is that the energy given off by the peanut to heat up the water is only 40% of the total energy given off in combustion, you need to work out the 100%. (was confused there for a sec :D)
 
  • #3
No. It means only 40% of the peanut's energy goes into the water
 
  • #4
what so how am i meant to calulate the other 60% that's not possible?
 
  • #5
Of course it's possible, that's like me saying to you;

You have 4 apples, which is 40% of the total number of apples from the bag, how many apples were in the bag?
 
  • #6
er could you put that to me algerbarically please... i mean it makes sense if it was 50% all you do is double it
 
  • #7
could it be .4x=(Joules calulated)?
 
  • #8
0.0

From 50% to 100% you times by 2...

From 40% to 100% you times by...

And ^ yes you're right.
 
  • #9
:smile:
Chewy0087 said:
Of course it's possible, that's like me saying to you;

You have 4 apples, which is 40% of the total number of apples from the bag, how many apples were in the bag?

Beat me to it again.
Although I considered replying earlier
in similar vein I just couldn't bear to do it.

David
 
  • #10
lawl =D
 

FAQ: Calculating Food Value of a Peanut Through Thermodynamics: Efficiency and Joules

What is simple thermodynamics?

Simple thermodynamics is a branch of science that deals with the study of energy and its transformations in physical systems. It is based on a set of fundamental principles and laws that govern the behavior of energy in different systems.

What are the laws of thermodynamics?

The laws of thermodynamics are a set of fundamental principles that govern the behavior of energy in physical systems. They include the first law, which states that energy cannot be created or destroyed, only transferred or converted from one form to another, and the second law, which states that the total entropy of a closed system always increases over time.

How is simple thermodynamics applied in real-world situations?

Simple thermodynamics is applied in various fields, such as engineering, chemistry, and physics, to understand and predict the behavior of energy in different systems. It is used, for example, in designing efficient engines, predicting chemical reactions, and understanding the behavior of materials under different conditions.

What is the difference between simple thermodynamics and classical thermodynamics?

Simple thermodynamics and classical thermodynamics are often used interchangeably, but there are some differences between them. Simple thermodynamics focuses on the basic principles and laws of thermodynamics, while classical thermodynamics also takes into account the effects of factors such as temperature, pressure, and volume on energy transformations.

What are some common misconceptions about simple thermodynamics?

One common misconception about simple thermodynamics is that it only applies to large-scale systems, when in fact, it can also be applied to smaller systems, such as molecules and atoms. Another misconception is that simple thermodynamics only deals with energy, when in reality, it also considers factors such as entropy, temperature, and pressure.

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