A ball is dropped from a building of height 100 m. At the same time, another ball is then thrown vertically up from the ground with a velocity V0. They meet each other at the middle. What is the speed V0 of the ball thrown vertically up?
a) 44.3 m/s
b) 9.8 m/s
c) 31.3 m/s
d) 19.6 m/s
e) 98.0 m/s