A robotic rover on Mars finds a spherical rock with a diameter of 10 centimeters. The rover picks up the rock and lifts it 20 centimeters straight up. The rock has a specific gravity of 4.65. The gravitational acceleration on Mars is 3.7 meters per second squared. If the robot's lifting arm has an efficiency of 30% and require 9 seconds to raise the rock 20 centimeters, how much power in watts did the arm use?