Fig. 2.36 shows the displacement-time graph for four bodies A, B, C and D. In each case state what information do you get about the acceleration (zero, positive or negative).

Explanation

A : Zero acceleration since slope (i.e., velocity) is constant, B : zero acceleration since slope is constant, C : negative acceleration (or retardation) since slope is decreasing with time, D: positive acceleration since slope is increasing with time.