1. The position function of a particle is s = t⁵ - 60t³, t 0, where s is measured in meters and t is measured in seconds. Find the acceleration at the instance when the velocity is zero (0).

2. A particle moves according to the equation of motion s = t⁵ - 10t³ + 18t, where s measured in meters and t is measured in seconds. Find the displacement and velocity when the acceleration is zero.