18. Two metal balls are the same size but one weighs twice as much as the othe dropped from the roof of a single story building at the same instant of time. the balls to reach the ground below will be: (A) about half as long as for the heavier ball as for the lighter one. (B) about half as long as for the lighter ball as for the heavier one. (C) about the same for both balls. (D) considerably less for the heavier ball, but not necessarily half as long. (E) considerably less for the lighter ball, but not necessarily half as long.