A lift is held up by two steel cables, each with length $10\,\text{m}$ and diameter $0.5\,\text{cm}$. When a man with mass $80\,\text{kg}$ gets into the lift, the cables lengthen by $1\,\text{mm}$. What is the best estimate for the Young modulus of the steel?
- A$2 \times 10^{10}\,\text{N m}^{-2}$
- B$4 \times 10^{10}\,\text{N m}^{-2}$
- C$2 \times 10^{11}\,\text{N m}^{-2}$
- D$4 \times 10^{11}\,\text{N m}^{-2}$