There is an Arc Autoshape (Basic Shapes). You can format the line as broken
or dotted and change its weight as required. You can duplicate the shape and
edit it as required to show the diminishing height of the bounce. The
initial arc is sideways but can be rotated. It begins as a quarter of a
circle or ellipse but can be drawn longer or smaller using the yellow
diamonds. To draw a circular arc, press Shift while drawing.
