Answer:
14875 kilojoules
Explanation:
m = Mass of rocket = 1400 kg
F = Force of the propulsion = 80 kN
u = Initial velocity of the rocket = 30 m/s
v = Final velocity of the rocket = 55 m/s
Work done by the rocket is given by the kinetic energy
[tex]K=\frac{1}{2}m(v^2-u^2)\\\Rightarrow K=\frac{1}{2}1400(55^2-30^2)\\\Rightarrow K=1487500\ J[/tex]
The net work done on the rocket is 1487500 Joules or 14875 kilojoules