A steel spring has a spring constant of $150\,\text{N m}^{-1}$. If a $25\,\text{N}$ weight is suspended from the spring, its stretched length becomes $55\,\text{cm}$. What was the spring’s original length?
- A$0.38\,\text{m}$
- B$0.49\,\text{m}$
- C$0.61\,\text{m}$
- D$0.72\,\text{m}$