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. The final temperature of both objects is:

Question

Quizplus · Accepted Answer

When A and B are placed in thermal contact, heat will flow from the hotter object to the cooler object until they reach thermal equilibrium at some final temperature, T. We can use the equation:

Q = mcΔT

where Q is the heat transferred, m is the mass of the object, c is the specific heat capacity of the object, and ΔT is the change in temperature. Since the objects are isolated, the total heat transfer is zero, so we can set up the equation:

mA cA (T - 300 K) + mB cB (T - 450 K) = 0

We know that cB = 2cA, so we can substitute and simplify:

mA cA (T - 300 K) + 2mA cA (T - 450 K) = 0

3mA cA (T - 375 K) = 0

T - 375 K = 0

T = 375 K

Therefore, the final temperature of both objects is 375 K, which is closest to choice C) 400 K.

The Heat Capacity of Object B Is Twice That of Object