As a result of doing work, a person supplies a machine with 1100 J of energy in 12 seconds. The machine in turn does work and delivers 900 J of energy in 14 seconds to some object. What is the efficiency of this machine?
To find the efficiency of a machine, you need to divide the useful output energy by the input energy and multiply by 100 to express it as a percentage.
In this case, the useful output energy is 900 J, and the input energy is 1100 J. The efficiency can be calculated using the following formula:
Efficiency = (Useful output energy / Input energy) * 100
Substituting the given values into the formula:
Efficiency = (900 J / 1100 J) * 100
Now, let's solve the equation:
Efficiency = (0.8182) * 100
Efficiency ≈ 81.82%
Therefore, the efficiency of this machine is approximately 81.82%.