Consider a particle moving on a straight line path over the time interval t=0 seconds to t=9 seconds, with its position (measured in meters) given by s(t), velocity given by v(t)=s'(t), and acceleration given by a(t)=v' (t)=s'' (t).Assume a(t)=2t-6 and v(0)=s(0)=0.

(a) Find s(1).

(b) What is the average acceleration (with units m/(s² )) over the time interval t=0 to t=9?