A model rocket, initially at rest on the ground, accelerates straight upward from rest with a time-varying acceleration given by a(t) = (1.2t) m/s2. This powered launch period lasts for time t = 2.1 s until fuel is exhausted. After that, the rocket continues to move upwards but under only the influence of gravity. Ignore air resistance and take g = 9.81 m/s2.
Find the maximum height in meters reached by the rocket relative to the ground.