To calculate the efficiency of each machine, we use the formula:
\[ \text{Efficiency} = \left( \frac{\text{Output Work}}{\text{Input Work}} \right) \times 100 \]
Now, let's calculate the efficiency for each machine:
Machine A:
- Output Work = 750 J
- Input Work = 1,500 J
- Efficiency = \( \left( \frac{750}{1500} \right) \times 100 = 50% \)
Machine B:
- Output Work = 1,000 J
- Input Work = 4,000 J
- Efficiency = \( \left( \frac{1000}{4000} \right) \times 100 = 25% \)
Machine C:
- Output Work = 450 J
- Input Work = 600 J
- Efficiency = \( \left( \frac{450}{600} \right) \times 100 = 75% \)
Machine D:
- Output Work = 3,000 J
- Input Work = 5,000 J
- Efficiency = \( \left( \frac{3000}{5000} \right) \times 100 = 60% \)
Now, summarizing the efficiencies:
- Machine A: 50%
- Machine B: 25%
- Machine C: 75%
- Machine D: 60%
The machine with the highest efficiency is Machine C, with an efficiency of 75%.