A body is projected from the ground at an angle of \( 45^\circ \) with the horizontal. Its velocity after \( 2 \, \text{s} \) is \( 20 \, \text{ms}^{-1} \). The maximum height reached by the body during its motion is _______ \( \text{m} \). (use \( g = 10 \, \text{ms}^{-2} \) )
