What is the initial acceleration of the plane? What is the acceleration of the plane at the point of take-off?

During take-off a jet airplane of mass 10000kg can produce a maximum thrust of 40kN, At the point of take-off, the plane experiences a drag force of 20kN.
a)Calculate the initial acceleration of the plane.
b)Calculate the acceleration of the plane at the point of take-off.

1 Answer
Mar 12, 2017

Initially, the acceleration is 4 m/s^2. At takeoff, it is 2 m/s^2.

Explanation:

In both cases, we need to evaluate the net force acting on the plane. This net force will, according to Newton's second law, be equal to ma, and because we know the mass, the acceleration a can be found.

Initially, the only force is the thrust of the engines, so

F_"net" = ma = 40 000 N

a = (40 000)/ (10 000) = 4 m/s^2

At the point of takeoff, there is also a drag force of 20 000 N that opposes the thrust, leaving a net force of 40 000 - 20 000 = 20 000 N

F_"net" = ma = 20 000 N

a = (20 000)/ (10 000) = 2 m/s^2