A machine, which is 75 percent efficient uses 12 joules of energy in lifting up a 1 kg mass through a certain distance. The mass is then allowed to fall through that distance. What will its velocity be at the end of its fall?

• A. \[\sqrt{\text{32}}\text{ m}/\text{s}\]
• B. \[\sqrt{\text{24}}\text{ m}/\text{s}\]
• C. \[\sqrt{\text{l8}}\text{ m}/\text{s}\]
• D. \[\sqrt{\text{9}}\text{ m}/\text{s}\]