Answer:
solution:
when the engine are fired the rocket has a linear constant acceleration motion:

is the final velocity of the rocket
when the engines are fired it become equal to the initial velocity of the rocket,
when the engines are shut off

solve eq(1) and eq(2) we find

solving for
=364.65 m
Where
is the distance travelled by the rockets for shutting off the engine
when the engines are fired:

NOTE:
DIAGRAM IS ATTACHED