In a hydraulic lift, the surface area of the input piston is \( 6 \, \text{cm}^2 \) and that of the output piston is \( 1500 \, \text{cm}^2 \). If \( 100 \, \text{N} \) force is applied to the input piston to raise the output piston by \( 20 \, \text{cm} \), then the work done is __________ kJ.
