Step-by-step explanation:
The formula for work is

where x is the angle between the displacement and force.
F is the force that is currently being active.
D is the displacement.
We only want our force and displacement to be positve so we use the absolute value sign.
Since the rocket and the displacement is both upwards, the signs. between them is 0.
So since

We can just use that

First, we covert km to m.

Now, we can multiply.



N times Meters = J so our answer is
