A jetliner, travelling northward, is landing with a speed of 79 m/s. Once the jet touches down, it has 710 m of runway in which to reduce its speed to 7.4 m/s. Compute the the average accelaration (magnitude and direction) of the plane during landing.

Answer 1

v^2=u^2+2fs or f=(v^2-u^2)/2s
=(7.4^2-79^2)/(2*710)
=(54.76-6241)/1420=-4.36m/s^2
Negative acceleration (i.e. against the direction of motion)of 4.36m/s^2