\textbf{167.} The amplitude of oscillation of a 1\,kg mass attached to a spring with constant $5\,\dfrac{\text{N}}{\text{cm}}$ is 4\,cm, and it oscillates on a horizontal frictionless surface. If the potential energy of this oscillator at a point $0.2$ from the path is large, the speed of the oscillator at this moment is how many centimeters per second? (Ignore friction forces.)
(1) $20\sqrt{10}$ \qquad (2) $40\sqrt{10}$ \qquad (3) $30\sqrt{\Delta}$ \qquad (4) $40\sqrt{5}$