# Specific heat capacity & heat capacity

• ellieee
In summary, the ratio of specific heat capacity to heat capacity cannot be assigned a dimensionless numerical value, and the question is ill posed. The relevant information for solving the problem is the ratio of 'c' to 'mc', which can be represented as c/mc. The distractors in the question, such as Q=mcΔθ and Q=CΔθ, are not necessary for finding the correct answer. Additionally, the correct answer should have units.

#### ellieee

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

#### Attachments

• CamScanner 05-11-2021 15.18_5.jpg
14.1 KB · Views: 96
• IMG_20210511_154002_edit_18437293132082.jpg
16.3 KB · Views: 90
• CamScanner 05-11-2021 15.18_6.jpg
65.4 KB · Views: 83
Delta2
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.

Delta2