30 points! Please answer at least one and how you found it! :)
Find the Mechanical Advantage or Efficiency:
1.A winch lifts a 4,000N piano 1m by applying 500N over a distance of 10m.
2.A 100N force is applied to a bicycle in its top gear and 50N of force is output.
3.50 pounds of effort to lift a 100 pound box with a machine.
4.Impossible efficiency that violates conservation of energy