ANSWER

Step-by-step explanation
To find the time taken for the jet to cover the distance, we have to apply one of Newton's equations of motion to first find the acceleration:

where v = final velocity
u = initial velocity
a = acceleration
s = distance covered
Therefore, we have that:

Now, we apply another equation of motion to find the time:

That is:

Therefore, it takes 30 seconds for the jet to cover the distance.