Something is reproducing.
Answer:
a)
, b) 
Explanation:
a) The equation for vertical velocity is obtained by deriving the function with respect to time:

The velocities at given instants are, respectivelly:


AAaaahh yes, T'was that a lovely chap by the name of Copernicus, has discovered us a little secret, well. why dont you share?
Copernicus: well uh, i'm a bit shy
ME: who a gives a flying *bleep* about your feelings man! just man up an discover the earth's rotation already!