One end of a steel wire is fixed to the ceiling of an elevator moving up with an acceleration \( 2\,\text{m/s}^2 \) and a load of \( 10\,\text{kg} \) hangs from the other end. If the cross-section of the wire is \( 2\,\text{cm}^2 \), then the longitudinal strain in the wire is given. (Take \( g=10\,\text{m/s}^2 \) and \( Y=2.0\times10^{11}\,\text{N/m}^2 \)).
