Comparison of rarefraction and compression

Which statement correctly describes the relationship between frequency and wavelength?

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)