A girl is hanging from a bar in the gymnasium by her hands. She then raises her body until her chin is level with the bar. Her mass is $48\,\text{kg}$. She lifts herself upward by $0.25\,\text{m}$. The time taken is $2.0\,\text{s}$. What is the useful power she uses to lift herself up?
- A$6.0\,\text{W}$
- B$24\,\text{W}$
- C$60\,\text{W}$
- D$240\,\text{W}$