a test rocket is fired vertically from a well. A catapult gives it initially velocity 80.0 m/s at ground level. Its engines then fires and it accelerates upwards at 4.00m/s ^2 until it reaches 1000m. At this point its engines fail and the rocket goes into free fall with an acceleration of -9.80m/s ^2.
a. how long is the rocket above the ground?
b. what is the maximum altitude?
c. what is the velocity just before it collides with the earth?
I don't understand what is happening in this question.!
but I found time it to to get to 1000m (I got 10s). Then I found time it was in free fall (I got 14.2s) add time together to get total time above ground. It that correct? Then I do not know wehe to go from here.