The position function of a particle in rectilinear motion

Question

The position function of a particle in rectilinear motion is given by s(t) = 2t^3 – 21t^2 + 60t + 3 for t ≥ 0 with t measured in seconds and s(t) measured in feet. Find the position and acceleration of the particle at the instant when the particle reverses direction. Include units in your answer.

Answer 1

Use the second derivative to determine the inflection point.