Speed of sound
Newton’s Second law in fluid form gives us the “wave equation” for sound. From this, we get for the molecular displacement, y:
y(x,t) = A sin(kx +/- wt)
where v = w/k = (2pf / [2p/l]) = lf
and from the wave equation, v = [B/r]1/2
(this is just like v = [T/m]1/2 for a string).