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# The landing speed of an airplane is 360 kph. When it touches down, it puts on its brakes and reverses its engines. The retardation in....?

Cont..

its speed is 0.2 times the square root of its speed. Determine the length of runway in meters it will travel from the point of touchdown until it comes to a complete stop.

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- VamanLv 72 months ago
Assume dv/dt=-0.2 sqrt v. Integrate it

1/sqrt v dv/dt =- 0.2, 2 v^1/2=0.2t +c. Now find the time t0.

1/2 v^1/2 -1/2 v0^1/2= 0.2 t -1.2 t0. to is the landing time and can be put as 0. v0 is the landing velocity. Final velocity is 0. t= 1/2*10/2 sqrt V0. time t total= 5/2 sqrt Vo. I will try to complete it later.

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- Anonymous2 months ago
You have mental retardation

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