A simple seconds pendulum is constructed out of a very thin isotropic string of coefficient of linear exapansion $\alpha {\text{=20X10}}^{\text{-4}}{}^{0}C^{-1}$  and a heavy particle attached to one end . The free end of the string suspended from the ceiling of an elevator at rest. The pendulum keeps correct time at ${20}^{0}C$. When the temperature rises to ${50}^{0}C$, The elevator operator of 60kg being a student of physics accelerates elevator vertically up to keep correct time. The apparent weight of the operator is 

(106y) N Then y=……….