Newton's Law of Cooling & Specific Heat Capacity

In summary: Yes, you are correct in that the specific heat capacity can be determined using Newton's Law of Cooling. However, you would need to find the specific heat capacity of the object and then use that value to determine the k value.
  • #1
Bradley Sigma
2
0
Newton's Law of Cooling basically states (I believe):
TObj = (TInital-TEnv)ekt + TEnv
where k is a property of the material.

In the equation:
Q=mCΔT
Specific heat capacity, C, is also a material property.

So here's my question:
Is there a relation between Newton's Law's k and the specific heat capacity of the material?
Also, I'm in a debate whether Newton's Law requires a draft to be accurate. Any information either way would be useful.

Thanks
 
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  • #2
Bradley Sigma said:
Newton's Law of Cooling basically states (I believe):
TObj = (TInital-TEnv)ekt + TEnv
where k is a property of the material.

In the equation:
Q=mCΔT
Specific heat capacity, C, is also a material property.

So here's my question:
Is there a relation between Newton's Law's k and the specific heat capacity of the material?
Also, I'm in a debate whether Newton's Law requires a draft to be accurate. Any information either way would be useful.

Thanks

Yeah ,

http://www.tutorvista.com/content/physics/physics-iii/heat-and-thermodynamics/Newtons-law-cooling.php

Yeah , it requires draft to be "more" accurate...

I would like other members as well to post their views...
 
  • #3
Bradley Sigma said:
Newton's Law of Cooling basically states (I believe):
TObj = (TInital-TEnv)ekt + TEnv
where k is a property of the material.

In the equation:
Q=mCΔT
Specific heat capacity, C, is also a material property.

So here's my question:
Is there a relation between Newton's Law's k and the specific heat capacity of the material?

Thanks
The general law states that the rate of heat transfer is proportional to the temperature difference and the area of contact.
Solving for a body cooling in some environment with fixed temperature produces an expression like the one you propose. Only that for cooling the exponent is negative. Your solution correspond to a temperature that increases indefinitely in time, unless you assume k<0.
Indeed the time constant in the exponent depends on the specific heat capacity of the body (and its mass too).
 
  • #4
It's not that it requires a draft, merely that what it's in contact with has effectively a constant temperature. In air, some forced draft, rather than mere convection, will certainly be needed. But in principle it could be encased in a solid with a very high specific heat.
The concept of a Tobj also suggests the object maintains a uniform temperature, which would imply a very high conductance. In practice, the temperature profile through the object will tend to change over time. It is probably not right to take an average temperature and expect the equation to work exactly, but I could be wrong.
 
  • #5
sankalpmittal said:
Yeah ,

http://www.tutorvista.com/content/physics/physics-iii/heat-and-thermodynamics/Newtons-law-cooling.php

Yeah , it requires draft to be "more" accurate...

I would like other members as well to post their views...

Newton's Law of cooling can also be stated as
ln(TObj-TEnv) = kt+c
k can therefore be found by finding the gradient of the trend line of the natural logarithm of the difference in temperature between object and the environment as a function of time.
However, would I be correct in thinking that something similar cannot be done to obtain the specific heat capacity, as your link states k=K/mC, for which the mass can easily be found, but as both K and C are unknown, they cannot be determined to a specific value. I know that there are other ways of determining specific heat capacity, I'm just wondering if it can be done using Newton's Law of Cooling.
 

FAQ: Newton's Law of Cooling & Specific Heat Capacity

1. What is Newton's Law of Cooling?

Newton's Law of Cooling states that the rate of change of temperature of an object is proportional to the difference between its current temperature and the temperature of its surroundings. This means that an object will cool down or heat up at a faster rate if there is a larger temperature difference between the object and its surroundings.

2. How is Newton's Law of Cooling applied in real life?

Newton's Law of Cooling is commonly used in industries such as food and beverage, where the rate of cooling of products is important for preservation and quality control. It is also used in weather forecasting to predict the cooling of the Earth's surface overnight.

3. What is specific heat capacity?

Specific heat capacity is the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius. It is a measure of how much energy is needed to change the temperature of a substance, and it differs for different materials.

4. How is specific heat capacity related to Newton's Law of Cooling?

Specific heat capacity is used in the calculation of the rate of cooling or heating of an object according to Newton's Law of Cooling. It determines how quickly an object will change its temperature in response to a temperature difference with its surroundings.

5. Can Newton's Law of Cooling and specific heat capacity be used for all substances?

No, Newton's Law of Cooling and specific heat capacity are applicable to most substances, but there are some exceptions. For example, substances that undergo a phase change, such as melting or boiling, have different rates of cooling or heating compared to those that do not undergo a phase change.

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