Principal of Conservation of Energy: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Principal of Conservation of Energy. Understanding the underlying formula is key to arriving at the correct answer below:

Efficiency $\eta = \frac{\text{Work output}}{\text{Work input}} = \frac{mgh}{F \cdot d} = \frac{75 \times 10 \times 3}{250 \times 12} = \frac{3}{4} = 75\%$.