Answer:
127.36 m/s
Step-by-step explanation:
velocity of plane with respect to air = 140 m/s due east
velocity of air with respect to ground = 31 m/s 30° west of north
Write the velocities in the vector forms



Let velocity of plane with respect to ground is given by vp/g
According to the formula of relative velocities




The magnitude of the velocity of plane with respect to the ground is given by

Thus, the velocity of plane with respect to the ground is given by 127.36 m/s.