* Full Circle: A clock hand makes a full circle (360 degrees) in 60 seconds.

* Degrees per Second: Therefore, in one second, it moves 360 degrees / 60 seconds = 6 degrees.

* Degrees in 30 Seconds: In 30 seconds, it moves 6 degrees/second * 30 seconds = 180 degrees.

* Radians: Since 180 degrees is equal to π radians, the second hand turns through π radians in 30 seconds.