An airplane is travelling north at 404.0 km/h. Ten minutes later it is travelling west at 433.0 km/h. What is the magnitude of the average acceleration vector in m/s2?

a = du/dt i + dv/dt j

original u = 0
final u = -433/3.6

original v = 404/3.6 m/s
final v = 0

ten min = 600 s

du/dt = -433/(3.6*600)
dv/dt = -404/(3.6*600)

|a| = sqrt [ (du/dt)^2 + (v/dt)^2 ]