Problem 17. A man is pushing two suitcases (M1 = 25 kg and M2 = 15 kg) as shown. The surface between the two suitcases and the surface between the lower suitcase (M1) and the floor are both described by Hk = 0.4 and µs = 0.5. (a) Find the maximum value of F for which the two suitcases accelerate but don't move relative to each other. (Hint: find the maximum possible acceleration for M2 using the maximum static friction force between the suitcases. Then find the force F needed to give M1 the same acceleration.) (b) If the applied force F were twice as large as you calculated in part (a), determine the acceleration of each suitcase.

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