Hi I really need help with this question... please provide a step by step explanation with the answer because I need to understand it.

Thanks!

A 406-kg pile driver (the figure below) is raised 12 m above ground.

(a) How much work must be done to raise the pile driver? [Answer in KJ]

(b) How much work does gravity do on the driver as it is raised? [Answer in kJ]

(c) The driver is now dropped. How much work does gravity do on the driver as it falls? [Answer in kJ]