The stone travels a horizontal distance of
x = (6.59 m/s) * t
after time t. For the stone to have covered 10.92 m, it would have traveled for
10.92 m = (6.59 m/s) * t
t = (10.92 m) / (6.59 m/s)
t ≈ 1.66 s
The stone's altitude at time t is
y = h - g/2 * t²
where g = 9.80 m/s² is the acceleration due to gravity, and h is the height of the bridge. The stone reaches the ground after about 1.66 s, so at that point y = 0 and we solve for h :
0 = h - 1/2 * (9.80 m/s²) * (1.66 s)²
h = 1/2 * (9.80 m/s²) * (1.66 s)²
h ≈ 13.5 m
