When airplanes land or take off, they always travel along a runway in the direct

Question

When airplanes land or take off, they always travel along a runway in the direction that is "into" the wind. This is because the "lift force" on an airplane wing depends on the speed of the airplane relative to the air (vrel mi/h). The lift force is proportional to v2rel. Consider a case in which a runway is parallel to the x axis, and the wind velocity is vwind = +18 mi/h (directed along +x).
(a) In what direction should the plane travel to takeoff (along +x or -x)?
i got -x
but i cant find part b) which is ....(b) Estimate the speed of a typical airplane (e.g. a Boeing 737) relative to the runway as it takes off to be about 142 mph. Find the ratio of the lift force for an airplane that travels into the wind, to the lift force when it travels in the opposite direction.

Explanation / Answer

into the wind you would add the 2 velocities whereas with the wind you would subtract the to velocities then take a ratio of the two. so (142+18)/(142-18)= 1.29 : 1 is the ratio of the lift force from taking off into the wind : lift force taking off with the wind.

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