Posted by bethany on .
A jetliner, traveling northward, is landing with a speed of 65 m/s. Once the jet touches down, it has 785 m of runway in which to reduce its speed to 5.0 m/s. Compute the average acceleration (magnitude and direction) of the plane during landing (take the positive direction to be northward).

physics 
bobpursley,
Vf^2=Vi^2+2*a*distance. compute a, if it turns out negative, it must be in the direction opposite the displacement vector.