A stone slides across an icy surface and travels a distance of x in time t while suffering uniform retardation. Which of the following pairs of quantities, plotted to represent the motion of the stone, would give a straight-line graph? A. x and t B. x and t2 C. x/t and t2 D. x/t and t E. x/t2 and t This is my approach to the problem: The initial velocity, u = at. Hence, the distance travelled by the stone, x = 0.5at2 x/t2 = (0.5at2)/t2 = 0.5a Since a is a constant, then a flat line would be represented in a graph of axes x/t2 and t. Also, in D., x/t = v, which decreases at a constant rate because of the constant deceleration, so this is another straight-line graph. Obviously, there must be something wrong with my reasoning because there can only be one, and not two answers for each multiple choice question.