A passenger weighing 70 kg sits in the seat of an aircraft flying at a speed of 720 km / h. Find the kinetic energy of the passenger

A passenger weighing 70 kg sits in the seat of an aircraft flying at a speed of 720 km / h. Find the kinetic energy of the passenger: a) in the reference system associated with the aircraft; b) in the frame of reference associated with the Earth.

In the frame of reference associated with the aircraft, the kinetic energy of the passenger is zero, since the passenger is at rest relative to the aircraft, relative to the Earth Ek = mv ^ 2/2 = 70 * 40000/2 = 1400 kJ.