Chapter 22, Problem 26A

When a space shuttle is in orbit and there appears to be no gravity in the cabin, why can a candle not stay lit?

To determine

To explain: The reason due to which a candle cannot stay lit in a space shuttle where there is no gravity.

Explanation of Solution

Introduction:

The process of heat transfer by the movement of heated particles is called convection.

When a candle is lit, the air around it gets hot and rises up due to convection. Cold air come in and takes its place. A candle requires oxygen to burn. When it uses up oxygen from the air around it, the air rises up and the candle uses oxygen from the fresh air that comes in to keep burning. However, in a space shuttle that has no gravity, the hot air around the candle does not rise up. The candle uses all the oxygen from the surrounding air and when it exhausts all the oxygen, it stops burning.

Conclusion:

A candle cannot stay lit in a space shuttle where there is no gravity as air around it does not rise up and the candle exhausts the oxygen present in the surrounding air after some time.