A particle moves in a straight line. At time \(t\) s, the acceleration, \(a \text{ ms}^{-2}\), of the particle is given by \(a = 36 - 6t\). The velocity of the particle is \(27 \text{ ms}^{-1}\) when \(t = 2\).

(a) Find the values of \(t\) when the particle is at instantaneous rest.

(b) Find the total distance the particle travels during the first 12 seconds.