Answer: The percentage efficiency of the machine is 31.15 %.
Explanation:
Input work done = [tex]9.63\times 10^3 joules[/tex]
Output work done = [tex]3.0\times 10^3 joules[/tex]
The efficiency of the machine = [tex]\frac{W_{Out}}{W_{In}}\times 100[/tex]
[tex]efficiency \%=\frac{3.0\times 10^3 joules}{9.63\times 10^3 joules}\times 100=31.15\%[/tex]
The percentage efficiency of the machine is 31.15 %.