Thermodynamics

Two objects at different temperatures are placed in thermal contact. In which direction will thermal energy flow?

A steel bridge is 100 m long at 20°C. The linear expansion coefficient of steel is $12 \times 10^{-6}$ $K^{-1}$. What is the change in length of the bridge when the temperature increases to 40°C?

A spherical balloon is filled with air. The initial volume of the balloon is $V_0$ at temperature $T_0$. If the temperature is increased to $2T_0$, and the volumetric thermal expansion coefficient is $\beta$, what is the new volume of the balloon, assuming the pressure remains constant?

A metal rod is heated. What happens to its dimensions?

A metal pot is placed on a hot stove. Is this an example of heating or cooling, and why?

Two systems are in thermal equilibrium. Which of the following statements is true about the rate of energy transfer between them?

Three objects with different masses and initial temperatures are placed in thermal contact inside an insulated container. After a long time, they reach thermal equilibrium. Which equation could be used to find the final temperature, assuming no phase changes?

Which of the following materials is best suited for insulating a building?

A glass window with an area of 2 $m^2$ and a thickness of 0.005 m has a temperature difference of 10°C between its inner and outer surfaces. If the thermal conductivity of the glass is 0.8 W/(m·K), what is the rate of heat transfer through the window?

What is the definition of thermal equilibrium between two or more systems?