Question: An hand crank is used to life a bucket of water from a well. The bucket and water have a combined mass of 12.0 kg and must be raised 8.5 m. The force used to lift this load is 40.0 N and must be applied over a total circular distance of 15.0 m. What is the efficiency of the system? Related Equations: W = (Force) (displacement) W useful = (mass) (gravity) (height) % Efficiency = useful work done / actual work done x 100% Attempt at a Solution: F = 40.0N m = 12.0kg h = 8.5m g= 9.8N/kg d= 15.0m w= ? w= (F)(d) w= (40.0N) (15.0m) w= 600J w useful = ? % Efficiency = ? W useful = m g h W useful = (12.0kg) (9.8N/kg) (8.5m) W useful = 999.6J w useful = 1000J % Efficiency = useful work done / actual work done x 100% % Efficiency = 1000J/600J x 100% % Efficiency = 166% The reason why I'm not sure I got the correct answer is because the efficiency of the system is over 100% instead of under.... ?_?