The straight bar passing parabola is a type of model used to demonstrate how a straight bar can pass through a parabola. This model is typically used in physics to illustrate how a straight bar can be manipulated to pass through a parabola. It is used to show how the shape of a parabola can be obtained by manipulating the orientation of the bar. The model is often used to demonstrate how to calculate the height of a parabola from the given parameters. It can also be used to demonstrate how the curvature of the parabola can be changed by manipulating the orientation of the bar.