The thrust force of each of the four engines can be calculated using the formula:

F = m*a

Where F is the thrust force, m is the mass of the airplane, and a is the acceleration.

Given that the airplane has a mass of 75 t and the resultant force is 120 kN, we can calculate the acceleration:

a = F/m = 120000 N / 75000 kg = 1.6 m/s^2

The frictional force is given by the formula:

F_f = u*m*a

Where F_f is the frictional force, u is the coefficient of friction, m is the mass of the airplane, and a is the acceleration.

Substituting the given values, we get:

F_f = 0.027 * 75000 kg * 1.6 m/s^2 = 3240 N

Since the resultant force of 120 kN is equal to the sum of the thrust and frictional forces, we can calculate the thrust force of each engine by subtracting the frictional force from the resultant force and dividing by 4 (since there are 4 engines).

Therefore, the thrust force of each engine is:

F_thrust = (120000 N - 3240 N)/4 = 29265 N

Congratulations, you now know the thrust force of each engine of the airplane during takeoff!