Rocket Out of Fuel: Time and Altitude

[afa]

Homework Statement

A rocket rises vertically, from rest, with an acceleration of 4.0 until it runs out of fuel at an altitude of 1500 . After this point, its acceleration is that of gravity, downward.
How long does it take to reach this point?

What maximum altitude does the rocket reach?

How much time (total) does it take to reach maximum altitude?
With what velocity does the rocket strike the Earth
How long (total) is it in the air?

Homework Equations

x=x+vt+.5at^2

The Attempt at a Solution

I found velocity when it runs out of fuel to be 110m/s don't know how to get the rest??

 

[stevenbhester]

We need more units! I'm guessing acceleration of 4.0m/s and an altitude of 1500 meters?