The equation of motion of a particle is s = t⁴ − 3t³ + t² − t, where s is in meters and t is in seconds. (Assume t ≥ 0.)
(a) Find the velocity, v(t), and acceleration, a(t), as functions of t.
v(t) = 4t³ - 9t² + 2t - 1
a(t) = ?