1. The problem statement, all variables and given/known data A particle executes simple harmonic motion with an amplitude of 2.51cm. At what positive displacement from the midpoint of its motion does its speed equal one half of its max speed? 2. Relevant equations A=2.51 cm x(t) = Acos(wt) v(t) = -Awsin(wt) vmax = |-Aw| 3. The attempt at a solution I just want to know how to find w so I can plug it into the vmax equation.