* Kinetic energy is the energy of motion.
* Motion means an object is changing position.
When the jet plane takes off, it's clearly in motion. This means it has kinetic energy.
Why your friend might disagree:
* They might be focusing on the *change* in kinetic energy. While there's a dramatic increase in kinetic energy as the plane accelerates, it starts from a non-zero kinetic energy (the energy it has while taxiing on the runway).
* They might be thinking about potential energy. The plane is gaining potential energy as it climbs higher, which could overshadow the increase in kinetic energy in their mind.
Ultimately, the plane has kinetic energy because it's moving, so you are correct!
