Projectile arc visualization for Jensen's inequality

Another Jensen's inequality visualization.

Picture the long parabola arc of a thrown ball from the thrower's hand to where it landed yonder. The first sense of average is the midpoint of the distance traveled between the thrower and the landing spot. To see the second sense of average, stand behind the thrower so the projectile's arc is just a vertical line. The second sense of average is the [...]. It's quite intuative how the mean height is lower than the height the ball reached at the mid-point.