Final answer:
The efficiency of a lever is calculated as the ratio of output work to input work. The given scenario leads to an unlikely efficiency of 150%, suggesting an error in the interpretation of the system as efficiencies cannot exceed 100%.
Step-by-step explanation:
The efficiency of a lever is calculated using the ratio of useful output work done to the total input work applied, normally expressed as a percentage. To find the efficiency of the system described, we first recognize that work is the product of force and distance. Since the distances from the fulcrum for the input and output forces are not given, we assume it is a first-order lever where input and output forces work at equal distances from the fulcrum, thus, the distances do not need to be considered.
The formula for efficiency is Efficiency (%) = (Work Output / Work Input) × 100%. In this case, Work Output is the force exerted by the load (600N), and Work Input is the force exerted by the effort (400N). Therefore, the efficiency would be (600N / 400N) × 100%, equals 150%.
However, the efficiency exceeding 100% is not possible in practical scenarios due to the conservation of energy principle and losses due to friction and other factors. This implies there might be an error in the system described or its interpretation.