Question

a jet airplane lands with a speed of 122 m/s and can accelerate uniformly at a max rate of - 6.2m/s2 as it comes to a rest. can this airplane land in 1.0 km runway

Answer 1

average speed during stop = 122/2 = 61 m/s

to get time to stop
v = 0 = 122 - 6.2 t
t = 122/6.2 = 19.7 seconds
so
distance = v average * t = 61*19.7 = 1200 meters

Off the end of the runway and 200 meters into the bleak ocean