Answer: The staircase is 14.28 m high.
Step-by-step explanation:
Given : Mass = 0.1 kg
Potential energy = 14 J
Potential energy is the energy occupied by the position of a substance. Therefore, formula for potential energy is as follows.
P.E = mgh
where,
m = mass
g = gravitational energy =

h = height of object
Substitute the values into above formula as follows.

Thus, we can conclude that the staircase is 14.28 m high.