Question

The heat capacity of object B is twice that of object A. Initially A is at 300 K and B is at 450 K. They are placed in thermal contact and the combination is isolated. If both objects are equal mass and no phase change takes place, then the final temperature of both objects is:

A) 375 K
B) 400 K
C) 425 K
D) 450 K

Answer 1

In a calorimetry problem involving thermal equilibrium, the final temperature of objects A and B with different heat capacities and temperatures will be a compromise between their initial temperatures. Given that the heat capacity of object B is twice that of A and no other information is provided, the final temperature is 375 K (Option A), as it's the mean of the initial temperatures.

Step-by-step explanation:

The question involves the concept of thermal equilibrium in physics, specifically within the context of calorimetry. When two objects with different temperatures and heat capacities are placed in thermal contact in an isolated system, they exchange heat until reaching a common final temperature. Object A, which is at 300 K, and Object B, which is at 450 K, will reach thermal equilibrium after heat flows from the hotter object to the cooler one.

Since Object B has twice the heat capacity of Object A and they are of equal masses, Object B will experience a smaller change in temperature compared to Object A when the same amount of heat is transferred. The final temperature will be between their initial temperatures, but closer to the initial temperature of Object A due to its lower heat capacity. Using the conservation of energy, we can calculate the final temperature, but since this is a multiple-choice question, we can deduce that the correct answer is A) 375 K because it is the temperature value that's exactly in the middle of the initial temperatures and accounts for the doubled heat capacity of Object B.