A jetliner, traveling northward, is landing with a speed of 65.7 m/s. Once the jet touches down, it has 817 m of runway in which to reduce its speed to 5.93 m/s. Compute the average acceleration (magnitude and direction) of the plane during landing (take the direction of the plane's motion as positive).
Vfinal^2 - Vinitial^2 = 2 a X
Solve for the acceleration, a.
It will be negative.
X = 817 m