Answer :
Given that the mass of airliner is
[tex]m=\text{ 7.7}\times10^4\text{ kg}[/tex]Also, the kinetic energy is given by
[tex]KE=1.3\times10^9\text{ J}[/tex]The Kinetic energy is given by the formula
[tex]KE=\frac{1}{2}mv^2[/tex]Here, v is the speed of an airliner. The speed can be calculated as
[tex]v=\sqrt[]{\frac{2KE}{m}}[/tex]Substituting the values, speed will be
[tex]\begin{gathered} v=\sqrt[]{\frac{2\times1.3\times10^9}{7.7\times10^4}} \\ =\sqrt[]{33766.233} \\ =183.75\text{ m/s} \end{gathered}[/tex]