A roller coaster has two vertical loops one after the other. The roller coaster has a speed of 7m/s at the top of the first loop with a height of 22.2m. It then proceeds around the second vertical loop with a height of 15.0m. What is the speed of the roller coaster at the top of the second vertical loop?
a.7m/s b.13.8m/s c.8.40m/s d.9.24m/s e.11.2m/s