We are given an initial temperature of the system, T1, as:
T1 = 300 K
After the divider is removed, the system will reach thermal equilibrium. According to the second law of thermodynamics, heat will flow from the hotter object to the colder object until the temperatures equalize.
This means the final temperature of the system after the divider is removed will be somewhere in between the initial temperatures of the two parts.
So considering the four answer choices:
A) 100 K - This is too low, the final temperature will be higher than 100K
B) 75 K - Also too low
C) 325 K - This is the initial temperature of one part, so the final temperature cannot be 325K
D) 185 K - This is a plausible final temperature in between 100K and 300K
Therefore, the answer is likely to be D) 185 K
In short, the key points are:
Heat will flow from the hotter to colder object until temperatures equalize
The final temperature will be somewhere in between the initial temperatures of the two parts
Answer choices A,B and C are too low or the same as one of the initial temperatures
Only D) 185K is a plausible intermediate temperature between 100K and 300K