a model is a simplified version of a physical system that would be too complicated to analyze in full detail.
we ignore the size, shape and rotation of the ball by representing it as a point object or particle. we ignore air resistance by making the ball move in a vacuum, and make the weight a constant. this process is what is meaned by “idealizing” the model
a useful model simplifies a problem enough to make it manageable, yet keeps its essential features.
the validity of the predictions we make using a model is limited by the validity of the model.
idealized models play a crucial role in physics.