Chapter 5.1, Problem 9R

To determine

To estimate the change in the thermal energy of the water in a pond.

Answer to Problem 9R

Change in thermal energy, $Q=42\times {10}^5\text{J}$

Explanation of Solution

Given data:

Mass of air in the room temperature, $M=1000\text{ kg}$

Specific heat, $S=4200\text{ J/(kg}\text{.}°\text{C)}$

Change in temperature, $\Delta T=1°\text{C}$

Formula used:

Change in the thermal energy ( Q ),

  $Q=M\times S\times (\Delta T)$

Calculation:

Change in the thermal energy ( Q ),

  $\begin{array}{l}Q=M\times S\times (\Delta T)\\ Q=1000\times 4200\times 1\\ Q=42\times {10}^5\text{J}\end{array}$

Conclusion:

Hence, the change in thermal energy is $Q=42\times {10}^5\text{J}$ .