Two bowling balls are rolling towards each other. The first has a mass of 5 kg and is rolling with a speed of 4 m/s to the right. The seconds has a mass of 6 kg and is rolling with a speed of 7 m/s to the left. After the collision, the first bowling ball rolls away with a speed of 5 m/s to the left. How fast is the second ball rolling after the collision? * a) 0.5 m/s
b) 7.5 m/s
c) 6.2 m/s
d) 0.9 m/s