Awave has the wavelength equal to 396 nm. what must be the frequency of this wave

A23.3-kg mass is attached to one end of a horizontal spring, with the other end of the spring fixed to a wall. the mass is pulled away from the equilibrium position (x = 0) and released. it then oscillates in simple harmonic motion with a frequency of 4.91 hz. if the mass’s maximum acceleration during the motion is 135 m/s2, how far from equilibrium was the mass initially pulled?