A rocket, initially at rest on the ground, accelerates straight upward from rest with constant (net) acceleration 53.9 m/s2 . The acceleration period lasts for time 6.00 s until the fuel is exhausted. After that, the rocket is in free fall.

Find the maximum height ymax reached by the rocket. Ignore air resistance and assume a constant free-fall acceleration equal to 9.80 m/s2 .