A jet airplane is travelling at $200 m/s$ The engine takes in $100\;m^3$ of air having mass $100 \;kg$ each second. The air is used to burn 5 kg fuel each second. The energy is used to compress the products of combustion and to eject them at the rear of the plane at $500 m/s$ relative to the plane. The thrust of the engine is

Question

$$(a)\;3.25 \times 10^4 \;N \quad (b)\;2 \times 10^4\;N \quad (c)\; 5.25 \times 10^4\;N \quad (d)\;7.25 \times 10^4 \;N$$