A baseball is thrown from the roof of 20.4m -tall building with an initial velocity of magnitude 13.9m/s and directed at an angle of 50.6 degrees above the horizontal.
(A) What is the speed of the ball just before it strikes the ground? Use energy methods and ignore air resistance.
(B) What is the answer for part (A) if the initial velocity is at an angle of 50.6 degrees below the horizontal?
(C) If the effects of air resistance are included, will part (A) or (B) give the higher speed?