Solve Basic Entropy Help Homework Statement

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In summary, the conversation discusses two identical microscopic objects and the number of ways to arrange energy in one of them based on the amount of energy present. The entropy of object A and B at specific energy levels is also mentioned. The formula for entropy and the number of states is provided as well. Finally, it is suggested to use the number of ways to calculate the entropy for the combined system of objects A and B.
  • #1
jchojnac
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Homework Statement



Object A and object B are two identical microscopic objects. The table below shows the number of ways to arrange energy in one of these objects, as a function of the amount of energy in the object.

E (joules) 4e-21 6e-21 8e-21 1e-20 1.2e-20 1.4e-20 1.6e-20
# ways 6 20 37 60 90 122 148

When there are 6e-21 joules of energy in object A, what is the entropy of this object?
SA = ? J/K

When there are 1e-20 joules of energy in object B, what is the entropy of this object?
SB = ? J/K

Now the two objects are placed in contact with each other. At this moment, before there is time for any energy flow between the objects, what is the entropy of the combined system of objects A and B?
SAB = ? J/K



Homework Equations



omega = (q+N-1)!/q!(N-1)!
S = kln(omega)


The Attempt at a Solution



I don't know how to get the quanta from the energy given...if that's how you do it? When i know the quanta i can find omega and and plug it into the entropy equation.
 
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  • #2
E: 4e-21, 6e-21, 8e-21, 1e-20, 1.2e-20, 1.4e-20, 1.6e-20
# ways: 6, 20, 37, 60, 90, 122, 148

This might be easier to read
 
  • #3
jchojnac said:

Homework Equations



omega = (q+N-1)!/q!(N-1)!
S = kln(omega)
There is a more basic definition for S=k·ln(#), where # is the number of states it is possible for the system to be in.

The formula using q and N seems to a way to calculate the number of states for a particular scenario ... however in this problem it is much easier to get #, just using the number of ways to arrange the given energy.

The Attempt at a Solution



I don't know how to get the quanta from the energy given...if that's how you do it? When i know the quanta i can find omega and and plug it into the entropy equation.
 
  • #4
Hey I have the same problem and I don't know how to do it as well
Can someone please help me?
What do you need to do after finding all of the S?
 
  • #5
S = k*ln(omega)

k= boltzman's constant
Boltzmann constant = 1.3806503 × 10-23 m2 kg s-2 K-1

omega= (q+n-1)!/q!(n-1)! = Number of ways

basically look at the energy asked and used the number of ways under for omega.

SAB = SA + SB

It worked for me hope i Helped
 

1. What is entropy?

Entropy is a measure of the disorder or randomness in a system. It is often referred to as the measure of the amount of energy that is unavailable for work in a system.

2. How is entropy calculated?

Entropy is calculated by dividing the heat absorbed or released by a system by the temperature at which the heat transfer occurs. It is represented by the symbol S and has units of joules per kelvin (J/K).

3. What is the relationship between entropy and disorder?

The higher the entropy, the higher the level of disorder in a system. This means that as entropy increases, the system becomes more random and less organized.

4. How does entropy relate to the second law of thermodynamics?

The second law of thermodynamics states that the total entropy of a closed system will always increase over time. This means that in any physical or chemical process, the overall entropy will either remain constant or increase.

5. Can entropy be decreased?

Yes, it is possible to decrease entropy in a local system, but this always results in an overall increase in the entropy of the universe. In other words, any decrease in entropy in one part of a system will be accompanied by an increase in entropy in another part of the system or the surrounding environment.

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