In problem 1-2, an object is moving along a horizontal coordinate line according to the formula s - f(t), where s, the directed distance from the origin, is in feel and t is in seconds. In each case, answer the following questions (see Examples 2 and 3).
(a) What are v(t) and a(t), the velocity and acceleration, at time t?
(b) When is the object moving to the right?
(c) When is it moving to the left?
(d) when is its acceleration negative?
(e) Draw a schematic diagram that shows the motion of the object.
1. s = 12t - 2t2
2. s = t3 - 6t2