Chapter 19, Problem 1CQ

To determine

Has the space capsule been heated?

Answer to Problem 1CQ

Solution: No, there is no heat$\left(Q\right)$ but rather transformation of kinetic energy $\left(K\right)$ into thermal energy $\text{Δ}{E}_{th}$.

Explanation of Solution

Given: Surface of the space capsule get very hot as it passes through the atmosphere at high speed.

The heat manifests when there is a transfer of energy between the system (shuttle) and the environment (Earth’s Atmosphere). In this problem, the shuttle before entering the Earth's atmosphere with high speed $\left(v\right)$, this means a high kinetic energy $\left(K\right)$. At the instant in which the molecules that make up the surface of the shuttle interact with the molecules of the Earth's atmosphere, kinetic friction is generated. As a result, the total mechanical energy $\text{Δ}{E}_{th}$ of the system is transformed into thermal energy $\text{Δ}{E}_{th}$, which translates into a decrease in the shuttle's kinetic energy. Therefore, there is no heat $\left(Q\right)$ but rather transformation of kinetic energy $\left(K\right)$ into thermal energy $\text{Δ}{E}_{th}$.

Conclusion:

No, there is no heat $\left(Q\right)$ but rather transformation of kinetic energy $\left(K\right)$ into thermal energy $\text{Δ}{E}_{th}$.