Kinematics
The velocity of a particle moving in the xy plane is given by v = [(6.0m/s2)t - (4.0 m/s3)t2]i + (8.0 m/s)j.
Assume t > O.
 (a) What is the acceleration when t = 3 s?
(b) When (if ever) is the acceleration zero?
(c) When (if ever) is the ve¬locity zero?
(d) When (if ever)does the speed equal 10 m/s?