The photograph shows an aeroplane which is powered by two engines.


ejected at a higher speed, providing the thrust for the aeroplane. The mass of air ejected by one of the engines in 1 minute is 34 600 kg.
The total thrust provided by the engines is 138 kN.
Calculate the speed, relative to the aeroplane, at which the air is ejected by the engines.
Speed of air = .......................................................