Rock a is dropped from a cliff and rock b is thrown upward from the same position on the cliff. a. when each rock reaches the ground at the bottom of the cliff, which rock has a greater velocity?

In the A case, v0=0, in the B case v0 >0, so v is greater in the B case. In other words, v is related to the kinetic energy, since the rock B has a larger kinetic energy in the beginning, it also has a larger kinetic energy (larger velocity) in the end.