Answer: 120 m
Explanation:
1) That the distance fallen is directly proportion of the square of the time, means:
distance = k * t^2 => k = distance / t^2
2) Use it for the two set of data given:
a) 39.2 m, 2 s => k = 39.2 m / (2 s)^2
b) x, 3.5 s => k = x / (3.5 s)^2
3) Equal the two expressions for k:
39.2 m / (2s)^2 = x / (3.5s)^2
=> x = 30.2 m * (3,5s)^2 / (2s)^2 = 39.2m * 12.25 / 4 = 120.05m = 120 m
