* Temperature and Molecular Motion: Temperature is a measure of the average kinetic energy of molecules. Higher temperatures mean molecules are moving faster.

* Air Resistance: When a steel ball moves through the air, it encounters resistance. This resistance is partially caused by collisions with air molecules.

* Faster Molecules, Less Resistance: At 25 degrees Celsius, the air molecules are moving faster than at -5 degrees Celsius. This means the steel ball will encounter less resistance from the air as it moves, allowing it to reach a higher speed.

Important Note: This assumes the steel ball is moving due to some external force (like being thrown or rolled). The temperature of the steel ball itself doesn't directly affect its speed, but the temperature of the air around it does.