Question

Consider a hot boiled egg in a spacecraft that is filled with air at atmospheric pressure and temperature at all times. Will the egg cool faster or slower when the spacecraft is in space instead of on the ground? Explain.

Short answer

Answer: A hot boiled egg will cool slower in space compared to on the ground, primarily due to the reduced convection in space caused by the lack of gravity.

Step-by-step solution

Identifying heat transfer mechanisms

When the egg is cooling, it transfers heat to its surroundings through two main processes: conduction and convection. Conduction occurs when heat is transferred between objects through direct contact, while convection is the transfer of heat through the movement of a fluid, such as air.

Evaluating conduction

In both cases, the egg is in direct contact with air, which will cause heat transfer through conduction. However, the rate of conduction does not change significantly with the change in environment as long as the air is at the same temperature and pressure. Thus, we can assume that conduction plays a more or less equal role in both cases.

Evaluating convection

Convection will play a different role when the spacecraft is in space compared to on the ground. On the ground, gravity causes the hot air around the egg to rise, which creates a natural air flow that increases the rate of heat transfer from the egg to the surrounding air. In space, where there is no gravity, this natural convection does not occur. The air around the egg does not rise, and the heat transfer due to convection is reduced.

Comparing the cooling process

Since the rate of conduction is more or less the same in both cases, the main factor that will affect the cooling rate of the egg is convection. As convection is less effective in space than on the ground due to the lack of gravity, the egg will cool at a slower rate in space than on the ground.

Conclusion

In conclusion, a hot boiled egg will cool slower when the spacecraft is in space compared to on the ground, primarily due to the reduced convection in space caused by the lack of gravity.