the equation of motion of a particle is s=2t-9t+4t+3, where s is in meters and t is in seconds. (assume t is less than or equal to 0) a) find the velocity and acceleration as functions of t. b) find the acceleration after 1 s

The equation of motion of a particle is s = 2t - 9t- + 4t + 3, where's is in meters and t is in seconds. (Assume t 2 0.) (a) Find the velocity and acceleration as functions of t. v (t ) = a(t) = (b) Find the acceleration after 1 s. a(1) = m/$2