You need the formula:  S = ut + 1/2 at^2 Where s = ditance you = initial velocity t= time a= acceleration which is 9.8 for gravity Now you = 0 because the stone has no initial velocity t = 3.1s The answer is: S= 0 + 1/2 (9.8 * 9.61) s = 47.08 meters … Read more