To calculate the acceleration of the jumbo jet, we can use Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass.

The net force acting on the jet is the sum of the thrust forces provided by its four engines:

$$F_{net} = 4(30000 N) = 120000 N$$

Now, using the formula:

$$a = F_{net} / m$$

where a is acceleration, Fnet is the net force, and m is the mass of the jet, we can calculate the acceleration:

$$a = 120000 N / 30000 kg = 4 m/s²$$

Therefore, the 747 jumbo jet experiences an acceleration of 4 meters per second squared when the thrust for each of its four engines is 30000 N.