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& Two runners are running next to each other when one decides to speed up at constant acceleration a. The second runner notices the acceleration after a short time interval **#x2206;t when the distance between the runners is d. The second runner accelerates at the same acceleration. Represent their motions with a motion diagram and position-versus-time graph (both graph lines on the same set of axes). Use any of the representations to predict what will happen to the distance between the runners—will it stay d. increase. or decrease? Assume that the runners continue to have the same acceleration for the duration of the problem.
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