A rocket blasts off vertically from rest on the launch pad with an upward acceleration of 2.30 m/s^2. At 10.0 s after blastoff, the engines suddenly fail, which means that the force they produce instantly stops.

How high above the launch pad will the rocket eventually go?
got it....142 m

Find the rocket's velocity at its highest point.
got it....0 m/s

Find the magnitude of the rocket's acceleration at its highest point.
got it....9.8 m/s^2

Find the direction of the rocket's acceleration at its highest point.
got it....downward

How long after it was launched will the rocket fall back to the launch pad?
got it....17.7 s

How fast will it be moving when it does so?
AHHHH!!!! I don't know....

At the top, it has no KEnergy, only PEnergy. So at the bottom, the PEnergy is converted to Kenergy.
mgh= 1/2 mv^2.

The other way..
v= sqrt(2gh) from kinetics.