Answer:
  v =[tex]\sqrt{\frac{k}{m} }[/tex]   x
Explanation:
For this exercise let's use the important topic of conservation of energy
starting point. Spring compression point
     Em₀ = K_e = ½ k x²
final point. When the spring is not compressed
     Em_f = K = ½ m v²
as they indicate that there is no friction, the energy is conserved
     Em₀ = Em_f
     ½ k x² = ½ m v²
     v =[tex]\sqrt{\frac{k}{m} }[/tex]   x
