posted by josh .
a ball is thrown vertically upward at a speed of 45 m/s. how long does it take to return to the ground?
Tr = (V-Vo)/g = (0-45)/-9.8 = 4.59 s. =
Tf = Tr = 4.59 s. = Fall time.
Tr + Tf = 4.59 + 4.59 = 9.2 s. = Time to
return to Gnd.