A jetliner, traveling northward, is landing with a speed of 83.8 m/s. Once the jet touches down, it has 750 m of runway in which to reduce its speed to 11.4 m/s. Compute the average acceleration (magnitude and direction) of the plane during landing (take the direction of the plane's motion as positive).
V^2 = Vo^2 + 2a*d
V = 11.4 m/s
Vo = 83.8 m/s
d = 750 m.
Solve for a. It should be negative.