A motor is employed to raise a load through a vertical distance of $0.50\,\text{m}$, as illustrated. The load has a weight of $40\,\text{N}$. The motor has a power rating of $20\,\text{W}$ and the system operates at $25\%$ efficiency. How long does it take to raise the load?
- A$0.040\,\text{s}$
- B$0.25\,\text{s}$
- C$4.0\,\text{s}$
- D$40\,\text{s}$