A 9.6 kg box, initially moving at a speed of 7.8 m/s, slides across the floor and comes to a stop after 2.4 seconds.
A) What is the coefficient of kinetic friction?
B) How far does the box move?
C) If you place a 5 kg block in the box, increasing the total mass to 11 kg, and then launch this heavier box with an initial speed of 7 m/s, how long does it take to stop?