1. The problem statement, all variables and given/known data The accompanying graph of position x versus time t represents the motion of a particle. If p and q are both positive constants, the expression that best describes the acceleration a of the particle is 2. Relevant equations (A) a = - p - qt (B) a = - p + qt (C) a = p + qt (D) a = p - qt 3. The attempt at a solution option D is mentioned correct in a given solution of the problem. If it is correct then dv/dt = p - qt on itegration will give v = pt -0.5qt^2 +c., for inflexion pts on x-t curve v =0 ,this gives qt^2-2pt-2c=0 , one of the two roots of which becoming negative, which is not realistic with the given graph. I need help to know the real fault made by me.