In an aircraft carrier warship the runway is a 20 m long strip inclined at `theta = 20^(@)` to the horizontal. The launcher is effectively a large spring that pushes an aircraft of mass m = 2000 kg for first 5 m of the 20 m long runway. The jet engine of the plane produces a constant thrust of `6 xx 10^(4) N` for the entire length of the runway. The plane needs to have a speed of 180 kph at the end of the runway. Neglect air resistance and calculate the spring constant of the launcher. [`sin 20^(@) = 0.3` and `g = 10 m//s^(2)`]

Answer

`k=2.096xx10^(5) N//m`