3. The velocity of a particle can be described by the function V(t) = 4 t2 - 12t + 7 (m/s) a) What is the instantaneous acceleration of the particle at t = 4? b) What is the average acceleration at time interval 3s & 5 s? c) The velocity when time is 3.5 s? d) The velocity when acceleration is zero. e) acceleration when the particles momentarily stopped or changes direction