Kinematics

For each of the following situations, sketch a graph that is a possible description of position as a function of time for a particle that moves along the x axis. At t = 1 s, the particle has
(a) zero velocity and positive acceleration;
(b) zero veloc­ity and negative acceleration;
(c) negative velocity and posi­tive acceleration;
(d) negative velocity and negative accelera­tion.
(e) For which of these situations is the speed of the particle increasing at t = 1 s?