For a liquid-in-glass thermometer, the liquid column measures $2.0\,\text{cm}$ at $0\,^\circ\text{C}$ and rises to $10.0\,\text{cm}$ when it is heated to $100\,^\circ\text{C}$. Starting from P, what is the length of the liquid column at $30\,^\circ\text{C}$?
- A$2.3\,\text{cm}$
- B$3.0\,\text{cm}$
- C$5.0\,\text{cm}$
- D$7.0\,\text{cm}$