A cylindrical water tower has a spiral staircase around it in the shape of a helix of radius 3 meters. Between the ground and the top of the tower, the stairs make three full revolutions and climb by 9 meters. A worker carries a bucket of water up to the top. The combined mass of the worker and the water is m = 50 kg, and the gravitational force is mg downward, where 9 = 9.8 m/sec' is the acceleration due to gravity. Calculate the work done by the worker against gravity