From \( 18 \, \text{m} \) height above the ground a ball is dropped from rest. The height above the ground at which the magnitude of velocity equal to the magnitude of acceleration (in the same set of units) due to gravity is ____ \( \text{m} \).
(Take \( g = 10 \, \text{m}/\text{s}^{2} \) and neglect the air resistance)
