Answer:
78.4 m
Explanation:
To obtain the height of the cliff;
We can use the Relation to obtain the final velocity, v
v = u + at
a = acceleration due to gravity = 9.8m/s²
v = 0 + (9.8*4)
v = 0 + 39.2
v = 39.2 m/s
To obtain the Height, S
v² = u² + 2aS
39.2^2 = 0 + 2(9.8)S
39.2^2 = 0 + 19.6S
1536.64 = 19.6S
S = 1536.64 / 19.6
S = 78.4 m