At a construction site, a bucket of concrete of mass m1 = 2 kg hangs from a light (but strong) cable that passes over a light friction-free pulley and is connected to a box of mass m2 = 2 kg on a horizontal roof (see the figure). The cable pulls horizontally on the box, and a bag of gravel rests on top of the box. The system is not moving. The free fall acceleration is g = 10 m/s^2. Suddenly a worker picks up the bag of gravel causing the bucket to fall down. The coefficient of kinetic friction between the box and the roof is MK = 0.25. Find the speed of the bucket after it has descended a distance of h = 30 m, from rest. Gravel m2 Box MK m1 Concrete h O 17.32 m/s 30 m/s 0 6 m/s O 15 m/s O 12 m/s