1. The problem statement, all variables and given/known data Okay.. so I have tried to do this one but no luck. 2. Relevant equations w= 2 * pi* v 1/2 kA^2= 1/2mv^2 + mgh Alright so the question: The motion of a particle is given by x(t)= 25cm* cos 10t What time is the kinetic energy twice the potential energy? Not sure how to use a x(t) equation to incorporate mgh which deals motion in the y direction. Any guide would be appreciated.. Thanks!!