A wave pulse starts propagating in positive x-direction along a non-uniform wire of length 10 m with mass per unit length given $m=m_0+\alpha x$  and under a tension of 100 N. The time taken by the pulse to travel from the lighter end (x = 0) to the heavier end is (given $m_0={10}^{-2}kg{m}^{-1}$ and $\alpha =9\times {10}^{-3}kg{m}^{-2}$ ) (in sec)