Specify the unstretched length l0 of the spring of stiffness which will result in a ve...

Specify the unstretched length l₀ of the spring of stiffness which will result in a velocity of for the contact at A if the toggle is given a slight nudge from its null position at θ = 0. The toggle has a mass of 1.5 kg and a radius of gyration about O of 55 mm. Motion occurs in the horizontal plane.