Specific heat capacity & heat capacity

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SUMMARY

The discussion centers on the confusion between specific heat capacity and heat capacity, specifically the distinction between the symbols 'c' (specific heat capacity) and 'C' (heat capacity). The correct ratio to evaluate is specific heat capacity divided by heat capacity, represented as c/mc. The participants emphasize the importance of recognizing the physical dimensions of these quantities and the need for units in answers. Additionally, the question posed is deemed ill-structured, containing distractors that complicate the understanding of the core concepts.

PREREQUISITES
  • Understanding of thermodynamic concepts, specifically heat capacity and specific heat capacity.
  • Familiarity with the equations Q=mcΔθ and Q=CΔθ.
  • Knowledge of dimensional analysis in physics.
  • Ability to differentiate between lowercase 'c' and uppercase 'C' in thermodynamic contexts.
NEXT STEPS
  • Study the differences between specific heat capacity and heat capacity in detail.
  • Learn how to apply dimensional analysis to physical equations.
  • Explore common distractors in physics problems and strategies to identify relevant information.
  • Review the implications of units in thermodynamic calculations.
USEFUL FOR

Students in physics, educators teaching thermodynamics, and anyone seeking clarity on the concepts of heat capacity and specific heat capacity.

ellieee
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Homework Statement
what is the numerical value of the ratio ?
Relevant Equations
Q=mcθ
Q=mc
the answer is 1/2 , but when I did the working out, I got 2/1.. so I'm quite confused
 

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The ratio has physical dimension. You therefore cannot assign a dimensionless numerical value.
 
Orodruin said:
The ratio has physical dimension. You therefore cannot assign a dimensionless numerical value.
then are you able to explain the answer key ?
 
ellieee said:
then are you able to explain the answer key ?
The question is ill posed.
 
But with regards to how the question (being ill posed) wants you to do things ...

You have taken heat capacity / specific heat capacity instead of specific heat capacity / heat capacity.
 
Orodruin said:
But with regards to how the question (being ill posed) wants you to do things ...

You have taken heat capacity / specific heat capacity instead of specific heat capacity / heat capacity.
how ..? isn't specific heat capacity = mcθ and heat capacity = cθ?
 
ellieee said:
isn't specific heat capacity = mcθ and heat capacity = cθ?
No.

Specific capacity is ‘c’ (lower case ‘c’).
Heat capacity is ‘C’ (upper case ‘C’)
C = mc
Warning: it's easy to mix up 'c' and 'C'!

That means you are simply being asked to find ##\frac c {mc}##.

Other notes...

The question contains distractors - unnecessary information to test your ability to identify the relevant information.

Q=mcΔθ gives the heat transferred when an object of mass m and specific heat capacity c changes temperature by Δθ. It is not required in this question.

Q = CΔθ gives the heat transferred when an object of heat capacity C changes temperature by Δθ. It is not required in this question.

The correct answer should have units (as already noted by @Orodruin in Post #2).

Edit - typo' corrected.
 
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