The Velocity of Ramon

Ramon, whose mass is $50 \text{ kg}$ , practices the radical sport bungee jumping. In a workout, it is released from the edge of an overpass, with zero initial velocity, attached to a track Elastic of natural length $L_0 = 15 \text{ m}$ and the constant elastic is $k = 250 \text{ N/m}$ .

When the strip is stretched 10 m beyond its natural length, then find the velocity (in $\text{m/s}$ ) of Ramon.