Which of the following objects- airplane, l train, person- would be easiest to model the motion of? which would be the most difficult?

Model the motion of a train would be the easiest. Model the motion of an airplane would be the easiest.

Explanation:

The advantages in modelling the motion of a train is that it goes on a rail with constant velocity most of the time, in a predictable direction .

On the other hand, an airplane is much more difficult because fluid dynamics (the interaction between air and the plane) has to be considered

the answer is kevlar