1. The problem statement, all variables and given/known data A vibration platform oscillates up and down with an amplitude of 10.4 cm at a controlled variable frequency. Suppose a small rock of unknown mass is placed on the platform. At what frequency will the rock just begin to leave the surface so that it starts to clatter? 2. Relevant equations ax(t) = -w^2 * Asin(wt) 3. The attempt at a solution I know I need to find the acceleration with the given amplitude but i still have two variables, omega and time in order to find that. Can anyone point me in the right direction?