The spring attached to the 10-kg mass is nonlinear, having the force–deflection relation...

The spring attached to the 10-kg mass is nonlinear, having the force–deflection relationship shown in the figure, and is unstretched when x = 0. If the mass is moved to the position and released from rest, determine its velocity v when x = 0. Determine the corresponding velocity if the spring were linear according to F = 4x, where x is in meters and the force F is in kilonewtons.