Compute all parts of given question:
Question: An 8 kg box with initial speed 6 m/s slides across the floor and comes to a stop after 1.7 s.
Part A: What is the coefficient of kinetic friction?
Part B: How far does the box move?
Part C: You put a 4 kg block in the box, so the total mass is now 12 kg, and you launch this heavier box with an initial speed of 6 m/s. How long does it take to stop?
Please show step by step process to the answer, explanation, as well as formulas.