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#